Exposure apparatus, exposure method, and method for producing device

ABSTRACT

A liquid immersion exposure apparatus includes a projection system having a last optical element, the projection system projecting a beam onto a substrate through an immersion liquid; a movable stage having a holder by which the substrate is held; a measurement member provided on the movable stage, the measurement member having a measurement portion covered with a light-transmissive material; a first alignment system by which an alignment mark is detected not through the immersion liquid; and a second alignment system which optically obtains, using the measurement member, first positional information of the beam projected by the projection system through the immersion liquid. In order to obtain the first positional information, the movable stage is moved so that the measurement member is under the projection system and a gap between the projection system and the measurement member is filled with the immersion liquid.

CROSS-REFERENCE

This is a divisional of U.S. patent application Ser. No. 11/399,537filed Apr. 7, 2006 (now U.S. Pat. No. 8,130,361), which in turn is acontinuation of International Application No. PCT/JP2004/015332 filedOct. 12, 2004 claiming the conventional priority of Japanese patentApplication No. 2003-350628 filed on Oct. 9, 2003 and No. 2004-045103filed on Feb. 20, 2004. The disclosures of each of the priorapplications are incorporated herein by reference in their entireties.

TECHNICAL FIELD

1. Field of the Invention

The present invention relates to an exposure apparatus, an exposuremethod, and a method for producing a device in which a substrate isexposed with a pattern via a projection optical system and a liquid.

2. Description of the Related Art

Microdevices such as semiconductor devices and liquid crystal displaydevices are produced by means of the so-called photolithographytechnique in which a pattern formed on a mask is transferred onto aphotosensitive substrate. The exposure apparatus, which is used in thephotolithography step, includes a mask stage for supporting the mask anda substrate stage for supporting the substrate. The pattern on the maskis transferred onto the substrate via a projection optical system whilesuccessively moving the mask stage and the substrate stage.

The microdevice is formed by overlaying a plurality of layers ofpatterns on the substrate. Therefore, when the pattern of the secondlayer or the following layer is projected onto the substrate to performthe exposure, it is important to accurately perform the alignmentprocess in which the pattern having been already formed on the substrateis positionally adjusted to the image of the pattern of the mask to besubjected to the exposure next time. The alignment system includes theso-called TTL system in which the projection optical system is used as apart of the mark-detecting system, and the so-called off-axis system inwhich an exclusive mark-detecting system is used not via the projectionoptical system. In the case of these systems as described above, thepositional adjustment is not performed directly for the mask and thesubstrate, but the positional adjustment is performed indirectly by theaid of a reference mark provided in the exposure apparatus (generallyprovided on the substrate stage). In particular, in the case of theoff-axis system, the baseline measurement is performed to measure thebaseline amount (information) which is the distance (positionalrelationship) between the detection reference position of the exclusivemark-detecting system and the projection position of the image of thepattern of the mask in a coordinate system which defines the movement ofthe substrate stage. When the overlay exposure is performed for thesubstrate, for example, the following operation is performed. That is,an alignment mark, which is formed in the shot area as the exposureobjective area on the substrate, is detected by the mark-detectingsystem to determine the position information (deviation or discrepancy)of the shot area with respect to the detection reference position of themark-detecting system. The substrate stage is moved from the position ofthe substrate stage obtained at that time by the baseline amount and theamount of the deviation of the shot area determined by themark-detecting system. Accordingly, the projection position of the imageof the pattern of the mask and the shot area are subjected to thepositional adjustment, and the exposure is performed in this state. Inthis way, the image of the pattern of the next mask can be overlaid onthe pattern which has been already formed on the substrate (shot area).

In recent years, it is demanded to realize the higher resolution of theprojection optical system in order to respond to the further advance ofthe higher integration of the device pattern. As the exposure wavelengthto be used is shorter, the resolution of the projection optical systembecomes higher. As the numerical aperture of the projection opticalsystem is larger, the resolution of the projection optical systembecomes higher. Therefore, the exposure wavelength, which is used forthe exposure apparatus, is shortened year by year, and the numericalaperture of the projection optical system is increased as well. Theexposure wavelength, which is dominantly used at present, is 248 nm ofthe KrF excimer laser. However, the exposure wavelength of 193 nm of theArF excimer laser, which is shorter than the above, is also practicallyused in some situations. When the exposure is performed, the depth offocus (DOF) is also important in the same manner as the resolution. Theresolution R and the depth of focus δ are represented by the followingexpressions respectively.R=k ₁·λ/NA  (1)δ=±k ₂·λ/NA²  (2)

In the expressions, λ represents the exposure wavelength, NA representsthe numerical aperture of the projection optical system, and k₁ and k₂represent the process coefficients. According to the expressions (1) and(2), the following fact is appreciated. That is, when the exposurewavelength λ is shortened and the numerical aperture NA is increased inorder to enhance the resolution R, then the depth of focus δ isnarrowed.

If the depth of focus δ is too narrowed, it is difficult to match thesubstrate surface with respect to the image plane of the projectionoptical system. It is feared that the focus margin is insufficientduring the exposure operation. Accordingly, the liquid immersion methodhas been suggested, which is disclosed, for example, in InternationalPublication No. 99/49504 as a method for substantially shortening theexposure wavelength and widening the depth of focus. In this liquidimmersion method, the space between the lower surface of the projectionoptical system and the substrate surface is filled with a liquid such aswater or any organic solvent so that the resolution is improved and thedepth of focus is magnified about n times by utilizing the fact that thewavelength of the exposure light beam in the liquid is 1/n as comparedwith that in the air (n represents the refractive index of the liquid,which is about 1.2 to 1.6 in ordinary cases).

Of course, it is also important for the liquid immersion exposureprocess that the positional adjustment is accurately performed betweenthe image of the pattern of the mask and the respective shot areas onthe substrate. It is important that the baseline measurement and thealignment process can be performed accurately when the positionaladjustment between the substrate and the image of the pattern of themask is indirectly performed via the reference mark as described above.

Further, not only the reference mark but also various types of sensorsand the like are arranged around the surface of the substrate stage.When such an instrument is used, it is necessary to avoid the leakageand the inflow of the liquid as much as possible. Any inconvenience maypossibly arise as well due to the inflow of the liquid into thesubstrate stage. Therefore, it is necessary to avoid the inflow of theliquid.

SUMMARY OF THE INVENTION

The present invention has been made taking the foregoing circumstancesinto consideration, an object of which is to provide an exposureapparatus and an exposure method which make it possible to suppress theleakage and the inflow of the liquid. Another object of the presentinvention is to provide an exposure apparatus and an exposure methodwhich make it possible to accurately perform the alignment process evenin the case of the liquid immersion exposure. Still another object ofthe present invention is to provide a method for producing a deviceusing the exposure apparatus, and a method for producing a device usingthe exposure method.

In order to achieve the objects as described above, the presentinvention adopts the following constructions.

According to a first aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a substrate stage which is movable whileholding the substrate; a first detecting system which detects analignment mark on the substrate held by the substrate stage and whichdetects a reference provided on the substrate stage; and a seconddetecting system which detects the reference provided on the substratestage via the projection optical system; wherein the reference, which isprovided on the substrate stage, is detected not through the liquid byusing the first detecting system, and the reference, which is providedon the substrate stage, is detected via the projection optical systemand the liquid by using the second detecting system to determine apositional relationship between a detection reference position of thefirst detecting system and a projection position of the image of thepattern.

According to the present invention, when the reference on the substratestage is detected by the first detecting system, the detection isperformed not through the liquid. Accordingly, the reference can bedetected satisfactorily without being affected, for example, by thetemperature change of the liquid. It is unnecessary to construct thefirst detecting system so that the first detection signal is adapted tothe liquid immersion. It is possible to use any conventional detectingsystem as it is. When the reference on the substrate stage is detectedby using the second detecting system, the detection is performed via theprojection optical system and the liquid while filling the space on theimage plane side of the projection optical system with the liquid, inthe same manner as in the liquid immersion exposure. Accordingly, it ispossible to accurately detect the projection position of the image ofthe pattern on the basis of the detection result. The baseline amount(baseline information), which is the positional relationship (distance)between the detection reference position of the first detecting systemand the projection position of the image of the pattern, can beaccurately determined on the basis of the respective pieces of theposition information about the substrate stage during the detectionoperations of the first and second detecting systems. The substrate(shot area) and the image of the pattern of the mask can be accuratelysubjected to the positional adjustment on the basis of the baselineamount when the overlay exposure is performed for the substrate as well.

According to a second aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a substrate stage which has a substrateholder for holding the substrate and which is movable while holding thesubstrate on the substrate holder; a first detecting system whichdetects an alignment mark on the substrate held by the substrate stage;and a second detecting system which detects a reference provided on thesubstrate stage through the liquid; wherein the substrate or a dummysubstrate is arranged on the substrate holder when the referenceprovided on the substrate stage is detected through the liquid by usingthe second detecting system.

According to the present invention, it is possible to avoid any inflowof a large amount of the liquid into the substrate holder and/or intothe substrate stage by arranging the substrate or the dummy substrate onthe substrate holder even when the detection is performed in a state inwhich the liquid is arranged or disposed on the reference. Therefore, itis possible to avoid the occurrence of any inconvenience including, forexample, the trouble and the electric leakage of the electric equipmentincluded in the substrate stage and the rust of respective membersincluded in the substrate stage which would be otherwise caused by theinflowed liquid.

According to a third aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a reference member which has an uppersurface having no difference in level; and a detecting system whichdetects a reference formed on the reference member in a state in which aspace between an end surface of the projection optical system and theupper surface of the reference member is filled with the liquid.

According to the present invention, the upper surface of the referencemember has no difference in level. Therefore, any bubble hardly remainsat the reference mark portion (level difference portion) on thereference member, for example, even when the dry state is switched intothe wet state. The liquid is prevented from remaining at the markportion as well when the wet state is switched into the dry state.Therefore, it is also possible to avoid the occurrence of any watertrace (so-called water mark) on the reference member.

According to a fourth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a substrate stage which has a substrateholder for holding the substrate and which is movable while holding thesubstrate on the substrate holder; a detector which detects whether ornot the substrate or a dummy substrate is held by the substrate holder;and a control unit which changes a movable area of the substrate stagedepending on a detection result obtained by the detector.

According to the present invention, the movable area of the substratestage is determined depending on whether or not the substrate or thedummy substrate is held by the substrate holder. Therefore, it ispossible to avoid the adhesion of the liquid to the holding surface ofthe substrate holder, and it is possible to avoid the inflow of theliquid into the substrate stage.

According to a fifth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a substrate stage which has a substrateholder for holding the substrate and which is movable while holding thesubstrate on the substrate holder; a liquid supply mechanism whichsupplies the liquid; a detector which detects whether or not thesubstrate or a dummy substrate is held by the substrate holder; and acontrol unit which controls operation of the liquid supply mechanism onthe basis of a detection result obtained by the detector.

According to the present invention, the operation of the liquid supplymechanism is controlled depending on whether or not the substrate or thedummy substrate is held by the substrate holder. Therefore, it ispossible to avoid the adhesion of the liquid to the holding surface ofthe substrate holder, and it is possible to avoid the inflow of theliquid into the substrate stage.

According to a sixth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a substrate stage which has a substrateholder for holding the substrate and which is movable while holding thesubstrate on the substrate holder; and a liquid supply mechanism whichsupplies the liquid onto the substrate stage only when the substrate ora dummy substrate is held on the substrate holder.

According to the present invention, the liquid supply mechanism suppliesthe liquid onto the substrate stage only when the substrate or the dummysubstrate is held on the substrate holder. Therefore, it is possible toavoid the adhesion of the liquid to the holding surface of the substrateholder, and it is possible to avoid the inflow of the liquid into thesubstrate stage.

According to a seventh aspect of the present invention, there isprovided an exposure apparatus which exposes a substrate by projectingan image of a pattern onto the substrate through a liquid; the exposureapparatus comprising a projection optical system which projects theimage of the pattern onto the substrate; a substrate stage which ismovable while holding the substrate; and a liquid immersion mechanismwhich forms a liquid immersion area on the substrate stage only when thesubstrate or a dummy substrate is held by the substrate stage.

According to the exposure apparatus of the seventh aspect, the liquidimmersion mechanism does not form the liquid immersion area on thesubstrate stage when the substrate or the dummy substrate is not held onthe substrate stage. Therefore, it is possible to effectively avoid theinflow of the liquid into the substrate stage.

According to an eighth aspect of the present invention, there isprovided an exposure apparatus which exposes a substrate by projectingan image of a pattern onto the substrate through a liquid; the exposureapparatus comprising a projection optical system which projects theimage of the pattern onto the substrate; and a substrate stage which hasa recess for holding the substrate and a flat portion arranged aroundthe recess, the flat portion being substantially flush with a surface ofthe substrate held by the recess; wherein an object is arranged in therecess on the substrate stage, and a liquid immersion area is formed onthe substrate stage only when a surface of the object is substantiallyflush with the flat portion.

According to the exposure apparatus of the eighth aspect, the liquidimmersion area is not formed on the substrate stage when the object isnot accommodated in the recess of the substrate stage or when the objectis not accommodated in the recess reliably. Accordingly, it is possibleto effectively avoid the inflow of the liquid into the substrate stage.

According to a ninth aspect of the present invention, there is providedan exposure apparatus which exposes a substrate by projecting an imageof a pattern onto the substrate through a liquid; the exposure apparatuscomprising a projection optical system which projects the image of thepattern onto the substrate; a stage which is movable on an image planeside of the projection optical system; a first detecting system whichdetects an alignment mark on the substrate and which detects a referenceprovided on the stage; and a second detecting system which detects thereference provided on the stage via the projection optical system;wherein the reference provided on the stage is detected not through theliquid by using the first detecting system, and the reference providedon the stage is detected via the projection optical system and theliquid by using the second detecting system to determine a positionalrelationship between a detection reference position of the firstdetecting system and a projection position of the image of the pattern.

According to the ninth aspect of the present invention, it is possibleto accurately perform the positional adjustment for the substrate (shotarea) and the image of the pattern.

According to a tenth aspect of the present invention, there is providedan exposure method for exposing a substrate by projecting an image of apattern onto the substrate via a projection optical system and a liquid;the exposure method comprising detecting position information about analignment mark on the substrate by using a first detecting system;detecting position information about a reference on a substrate stagewhich holds the substrate, by using the first detecting system; anddetecting the reference on the substrate stage via the projectionoptical system and the liquid by using a second detecting system aftercompletion of both of detection of the position information about thealignment mark and detection of the position information about thereference on the substrate stage by the first detecting system; whereina relationship between a detection reference position of the firstdetecting system and a projection position of the image of the patternis determined on the basis of a detection result of the positioninformation about the alignment mark obtained by the first detectingsystem, a detection result of the position information about thereference on the substrate stage obtained by the first detecting system,and a detection result of the position information about the referenceon the substrate stage obtained by the second detecting system, and theimage of the pattern and the substrate are subjected to positionaladjustment to successively project the image of the pattern onto each ofa plurality of shot areas on the substrate to expose the substrate.

According to this exposure method, the position information about theplurality of shot areas on the substrate is firstly determined bydetecting the alignment mark on the substrate by the first detectingsystem not through the liquid. Subsequently, the reference on thesubstrate stage is detected not through the liquid to determine theposition information thereof. Subsequently, the space on the image planeside of the projection optical system is filled with the liquid and theprojection position of the image of the pattern is determined bydetecting the reference on the substrate stage by the second detectingsystem via the projection optical system and the liquid. The baselineamount, which is the positional relationship (distance) between thedetection reference position of the first detecting system and theprojection position of the image of the pattern, is accuratelydetermined. After that, the space between the projection optical systemand the substrate is filled with the liquid to perform the liquidimmersion exposure for the substrate. Therefore, it is possible todecrease the number of times of the switching operations between the drystate in which the space on the image plane side of the projectionoptical system is not filled with the liquid and the wet state in whichthe space on the image plane side of the projection optical system isfilled with the liquid. Thus, it is possible to improve the throughput.The operation for detecting the reference by the first detecting systemand the operation for detecting the reference by the second detectingsystem via the projection optical system and the liquid are continuouslyperformed. Therefore, it is possible to avoid the inconvenience whichwould be otherwise caused such that the detection state, which isbrought about during the operation for detecting the reference by thesecond detecting system, is greatly varied from the detection statewhich is brought about during the operation for detecting the referenceby the first detecting system, and the baseline amount, which is thepositional relationship between the detection reference position of thefirst detecting system and the projection position of the image of thepattern, cannot be measured accurately. The reference can besatisfactorily detected without being affected, for example, by thetemperature change of the liquid by performing the detection not throughthe liquid when the reference on the substrate stage is detected by thefirst detecting system. Further, it is unnecessary that the firstdetecting system is constructed to be adapted to the liquid immersion.It is possible to use any conventional detecting system as it is. Whenthe reference on the substrate stage is detected by using the seconddetecting system, the detection is performed via the projection opticalsystem and the liquid while filling the space on the image plane side ofthe projection optical system with the liquid in the same manner as inthe liquid immersion exposure. Accordingly, it is possible to accuratelydetect the projection position of the image of the pattern on the basisof the detection result. The baseline amount, which is the positionalrelationship (distance) between the detection reference position of thefirst detecting system and the projection position of the image of thepattern, can be accurately determined on the basis of the respectivepieces of position information about the substrate stage during thedetecting operations of the first and second detecting systems. Thesubstrate (shot area) and the image of the pattern of the mask can beaccurately subjected to the positional adjustment on the basis of thebaseline amount even when the overlay exposure is performed for thesubstrate.

According to an eleventh aspect of the present invention, there isprovided an exposure method for exposing a substrate by projecting animage of a pattern onto the substrate through a liquid; the exposuremethod comprising detecting an alignment mark on the substrate held by asubstrate stage provided with a reference and a substrate holder, byusing a first detector; detecting the reference through the liquid byusing a second detector in a state in which the substrate or a dummysubstrate is arranged on the substrate holder; and performing positionaladjustment for the substrate and the image of the pattern on the basisof detection results obtained by the first and second detectors toexpose the substrate with the image of the pattern.

According to the exposure method of the eleventh aspect of the presentinvention, the substrate or the dummy substrate is arranged on thesubstrate holder when the reference provided on the substrate stage isdetected by the second detector through the liquid. Therefore, it ispossible to effectively avoid the inflow of the liquid into thesubstrate stage.

According to a twelfth aspect of the present invention, there isprovided an exposure method for exposing a substrate by projecting animage of a pattern through a liquid onto the substrate held by asubstrate holder of a movable substrate stage; the exposure methodcomprising detecting whether or not the substrate or a dummy substrateis held by the substrate holder; and setting a movable area of thesubstrate stage depending on an obtained detection result.

According to the exposure method of the twelfth aspect of the presentinvention, the movable area of the substrate stage is set, for example,such that the interior of the substrate stage is prevented from anyinflow of the liquid when it is detected that the substrate or the dummysubstrate is not held by the substrate holder.

According to a thirteenth aspect of the present invention, there isprovided an exposure method for exposing a substrate by projecting animage of a pattern through a liquid onto the substrate held by a movablesubstrate stage; the exposure method comprising detecting whether or notthe substrate or a dummy substrate is held by the substrate stage; andjudging whether or not a liquid immersion area is to be formed on thesubstrate stage depending on an obtained detection result.

According to the exposure method of the thirteenth aspect of the presentinvention, the supply of the liquid onto the substrate stage is stopped,for example, when it is detected that the substrate or the dummysubstrate is not held by the substrate stage. Therefore, it is possibleto avoid the inflow of the liquid into the substrate stage.

According to the present invention, there is provided a method forproducing a device, comprising using the exposure apparatus as describedabove. According to the present invention, there is provided a methodfor producing a device, comprising using the exposure method asdescribed above.

According to the present invention, the liquid immersion exposureprocess can be performed in a state in which the accurate positionaladjustment is achieved for the substrate (shot area) and the projectionposition of the image of the pattern. Therefore, it is possible toproduce the device which can exhibits the desired performance. Thedevice having the desired performance can be produced by using theexposure apparatus which is capable of suppressing the leakage and theinflow of the liquid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic arrangement illustrating an embodiment of anexposure apparatus of the present invention.

FIG. 2 shows a schematic arrangement illustrating a liquid supplymechanism and a liquid recovery mechanism.

FIG. 3 shows a schematic plan view illustrating the liquid supplymechanism and the liquid recovery mechanism.

FIG. 4 shows a plan view illustrating a substrate stage.

FIGS. 5A, 5B and 5C show a reference member.

FIG. 6 shows a flow chart illustrating an embodiment of an exposuremethod of the present invention.

FIG. 7 schematically shows another embodiment of a substrate stageaccording to the present invention.

FIG. 8 schematically shows another embodiment of the substrate stageaccording to the present invention.

FIG. 9 shows a plan view illustrating an embodiment of an exposureapparatus provided with a waiting place for a dummy substrate.

FIGS. 10A and 10B schematically show another embodiment of a substratestage according to the present invention.

FIGS. 11A and 11B illustrate the movement locus of the substrate stageaccording to the present invention.

FIG. 12 illustrates the movement locus of the substrate stage accordingto the present invention.

FIGS. 13A and 13B illustrate the operation of the liquid supplymechanism according to the present invention.

FIG. 14 shows a flow chart illustrating exemplary steps of producing asemiconductor device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

The exposure apparatus according to the present invention will beexplained below with reference to the drawings. However, the presentinvention is not limited thereto.

FIG. 1 shows a schematic arrangement illustrating an embodiment of anexposure apparatus of the present invention. With reference to FIG. 1,the exposure apparatus EX includes a mask stage MST which supports amask M, a substrate stage PST which supports a substrate P, anillumination optical system IL which illuminates, with an exposure lightbeam EL, the mask M supported by the mask stage MST, a projectionoptical system PL which performs the projection exposure for thesubstrate P supported by the substrate stage PST with an image of apattern of the mask M illuminated with the exposure light beam EL, and acontrol unit CONT which integrally controls the operation of the entireexposure apparatus EX.

The exposure apparatus EX of this embodiment is a liquid immersionexposure apparatus to which the liquid immersion method is applied inorder that the exposure wavelength is substantially shortened to improvethe resolution and the depth of focus is substantially widened. Theexposure apparatus EX includes a liquid supply mechanism 10 whichsupplies the liquid LQ onto the substrate P, and a liquid recoverymechanism 20 which recovers the liquid LQ from the substrate P. In thisembodiment, pure water is used for the liquid LQ. The exposure apparatusEX forms a liquid immersion area AR2 (locally) on at least a part of thesubstrate P including a projection area AR1 of the projection opticalsystem PL by the liquid LQ supplied from the liquid supply mechanism 10at least during the period in which the image of the pattern of the maskM is transferred onto the substrate P. Specifically, the exposureapparatus EX is operated as follows. That is, the space between thesurface (exposure surface) of the substrate P and the optical element 2disposed at the end portion of the projection optical system PL isfilled with the liquid LQ. The image of the pattern of the mask M isprojected onto the substrate P to expose the substrate P therewith viathe projection optical system PL and the liquid LQ between theprojection optical system PL and the substrate P.

The embodiment of the present invention will be explained as exemplifiedby a case using the scanning type exposure apparatus (so-called scanningstepper) as the exposure apparatus EX in which the substrate P isexposed with the pattern formed on the mask M while synchronously movingthe mask M and the substrate P in mutually different directions(opposite directions) in the scanning directions (predetermineddirections). In the following explanation, the X axis direction is thesynchronous movement direction (scanning direction, predetermineddirection) for the mask M and the substrate P in the horizontal plane,the Y axis direction (non-scanning direction) is the direction which isperpendicular to the X axis direction in the horizontal plane, and the Zaxis direction is the direction which is perpendicular to the X axisdirection and the Y axis direction and which is coincident with theoptical axis AX of the projection optical system PL. The directions ofrotation (inclination) about the X axis, the Y axis, and the Z axis aredesignated as θX, θY, and θZ directions respectively. The term“substrate” referred to herein includes those obtained by coating asemiconductor wafer surface with a resist, and the term “mask” includesa reticle formed with a device pattern to be subjected to the reductionprojection onto the substrate.

The illumination optical system IL is used so that the mask M, which issupported on the mask stage MST, is illuminated with the exposure lightbeam EL. The illumination optical system IL includes, for example, anexposure light source, an optical integrator which uniformizes theilluminance of the light flux radiated from the exposure light source, acondenser lens which collects the exposure light beam EL emitted fromthe optical integrator, a relay lens system, and a variable fielddiaphragm which sets the illumination area on the mask M illuminatedwith the exposure light beam EL to be slit-shaped. The predeterminedillumination area on the mask M is illuminated with the exposure lightbeam EL having a uniform illuminance distribution by the illuminationoptical system IL. Those usable as the exposure light beam EL radiatedfrom the illumination optical system IL include, for example, emissionlines (g-ray, h-ray, i-ray) in the ultraviolet region radiated, forexample, from a mercury lamp, far ultraviolet light beams (DUV lightbeams) such as the KrF excimer laser beam (wavelength: 248 nm), andvacuum ultraviolet light beams (VUV light beams) such as the ArF excimerlaser beam (wavelength: 193 nm) and the F₂ laser beam (wavelength: 157nm). In this embodiment, the ArF excimer laser beam is used. Asdescribed above, the liquid LQ is pure water in this embodiment, throughwhich even the ArF exposure light beam as the exposure light beam EL istransmissive. Those also capable of being transmitted through pure waterinclude the emission line (g-ray, h-ray, i-ray) in the ultravioletregion and the far ultraviolet light beam (DUV light beam) such as theKrF excimer laser beam (wavelength: 248 nm).

The mask stage MST is movable while holding the mask M. The mask stageMST is two-dimensionally movable in the plane perpendicular to theoptical axis AX of the projection optical system PL, i.e., in the XYplane, and it is finely rotatable in the OZ direction. The mask stageMST is driven by a mask stage-driving unit MSTD such as a linear motor.The mask stage-driving unit MSTD is controlled by the control unit CONT.A movement mirror 50, which is movable together with the mask stage MST,is provided on the mask stage MST. A laser interferometer 51 is providedat a position opposed to the movement mirror 50. The position in thetwo-dimensional direction and the angle of rotation of the mask M on themask stage MST are measured in real-time by the laser interferometer 51.The result of the measurement is outputted to the control unit CONT. Thecontrol unit CONT drives the mask stage-driving unit MSTD on the basisof the result of the measurement obtained by the laser interferometer 51to thereby position the mask M supported on the mask stage MST.

The projection optical system PL projects the pattern on the mask M ontothe substrate P at a predetermined projection magnification β to performthe exposure. The projection optical system PL includes a plurality ofoptical elements including an optical element (lens) 2 provided at theend portion on the side of the substrate P. The optical elements aresupported by a barrel PK. In this embodiment, the projection opticalsystem PL is based on the reduction system having the projectionmagnification β which is, for example, ¼ or ⅕. The projection opticalsystem PL may be any one of the 1× magnification system and themagnifying system. The projection optical system PL may be either aprojection optical system of the cata-dioptric type including catoptricand dioptric elements or a projection optical system of the catoptrictype including only a catoptric element. The optical element 2, which isdisposed at the end portion of the projection optical system PL of thisembodiment, is provided detachably (exchangeably) with respect to thebarrel PK. The optical element 2, which is disposed at the end portion,is exposed from the barrel PK. The liquid LQ of the liquid immersionarea AR2 makes contact with the optical element 2. Accordingly, thebarrel PK, which is formed of metal, is prevented from any corrosion orthe like.

The optical element 2 is formed of fluorite. Fluorite has a highaffinity for water. Therefore, the liquid LQ is successfully allowed tomake tight contact with substantially the entire surface of the liquidcontact surface 2 a of the optical element 2. That is, in thisembodiment, the liquid (water) LQ, which has the high affinity for theliquid contact surface 2 a of the optical element 2, is supplied.Therefore, the highly tight contact is effected between the liquid LQand the liquid contact surface 2 a of the optical element 2. The opticalelement 2 may be formed of quartz having a high affinity for water. Awater-attracting (lyophilic or liquid-attracting) treatment may beperformed to the liquid contact surface 2 a of the optical element 2 tofurther enhance the affinity for the liquid LQ.

The exposure apparatus EX has a focus-detecting system 4. Thefocus-detecting system 4 includes a light-emitting section 4 a and alight-receiving section 4 b. A detecting light beam is radiated in anoblique direction from the light-emitting section 4 a via the liquid LQonto the surface (exposure surface) of the substrate P. A reflectedlight beam thereof is received by the light-receiving section 4 b. Thecontrol unit CONT controls the operation of the focus-detecting system4. Further, the control unit CONT detects the position (focus position)of the surface of the substrate P in the Z axis direction with respectto a predetermined reference plane on the basis of the light-receivingresult of the light-receiving section 4 b. When the focus positions aredetermined at a plurality of points on the surface of the substrate Prespectively, the focus-detecting system 4 can also determine theposture of the substrate P in the inclined direction. A structure, whichis disclosed, for example, in Japanese Patent Application Laid-open No.8-37149, can be used for the focus-detecting system 4. Thefocus-detecting system 4 may also be of a type in which the detectinglight beam is radiated onto the surface of the substrate P not throughthe liquid.

The substrate stage PST is movable while holding the substrate P. Thesubstrate stage PST includes a Z stage 52 which holds the substrate P bythe aid of a substrate holder PSH, and an XY stage 53 which supports theZ stage 52. The XY stage 53 is supported on a base 54. The substratestage PST is driven by a substrate stage-driving unit PSTD such as alinear motor. The substrate stage-driving unit PSTD is controlled by thecontrol unit CONT. It goes without saying that the Z stage and the XYstage are provided as an integrated body. The position of the substrateP in the XY directions (position in the direction substantially inparallel to the image plane of the projection optical system PL) iscontrolled by driving the XY stage 53 of the substrate stage PST.

A movement mirror 55, which is movable together with the substrate stagePST with respect to the projection optical system PL, is provided on thesubstrate stage PST (Z stage 52). A laser interferometer 56 is providedat a position opposed to the movement mirror 55. The angle of rotationand the position in the two-dimensional direction of the substrate P onthe substrate stage PST are measured in real-time by the laserinterferometer 56. The result of the measurement is outputted to thecontrol unit CONT. The control unit CONT positions the substrate Psupported by the substrate stage PST in the X axis direction and the Yaxis direction by driving the XY stage 53 by the aid of the substratestage-driving unit PSTD in the two-dimensional coordinate system definedby the laser interferometer 56.

The control unit CONT controls the position (focus position) of thesubstrate P held by the Z stage 52 in the Z axis direction and theposition in the θX and θY directions by driving the Z stage 52 of thesubstrate stage PST by the aid of the substrate stage-driving unit PSTD.That is, the Z stage 52 is operated on the basis of the instruction fromthe control unit CONT based on the detection result of thefocus-detecting system 4. The angle of inclination and the focusposition (Z position) of the substrate P are controlled so that thesurface (exposure surface) of the substrate P is adjusted to match theimage plane to be formed via the projection optical system PL and theliquid LQ.

An auxiliary plate 57 is provided on the substrate stage PST (Z stage52) so that the substrate P is surrounded thereby. The auxiliary plate57 has a flat surface which has approximately the same height as that ofthe surface of the substrate P held by the substrate holder PSH. In thisarrangement, a gap of about 0.1 to 2 mm is provided between theauxiliary plate 57 and the edge of the substrate P. However, the liquidLQ scarcely flows into the gap owing to the surface tension of theliquid LQ. Even when any portion in the vicinity of the circumferentialedge of the substrate P is subjected to the exposure, the liquid LQ canbe retained under the projection optical system PL by the aid of theauxiliary plate 57. The substrate holder PSH may be provided as anothermember separately from the substrate stage PST (Z stage 52).Alternatively, the substrate holder PSH may be provided integrally withthe substrate stage PST (Z stage 52).

A substrate alignment system 5, which detects alignment marks 1 formedon the substrate P or a substrate side reference mark PFM formed on areference member 3 provided on the Z stage 52, is provided in thevicinity of the end portion of the projection optical system PL. A maskalignment system 6, which detects a mask side reference mark MFM formedon the reference member 3 provided on the Z stage 52 via the mask M andthe projection optical system PL, is provided in the vicinity of themask stage MST. A structure, which is disclosed, for example, inJapanese Patent Application Laid-open No. 4-65603, can be used for thesubstrate alignment system 5. A liquid-repellent cover (not shown) isprovided to avoid any adhesion of the liquid around the optical elementdisposed at the terminal end of the substrate alignment system 5(optical element disposed most closely to the substrate P and thesubstrate stage PST). The surface of the optical element disposed at theterminal end of the substrate alignment system 5 is coated with aliquid-repellent material. The adhesion of the liquid LQ is avoided aswell as an operator can easily wipe out the liquid even when the liquidadheres to the optical element disposed at the terminal end. A sealmember such as a V-ring, which is provided in order to avoid any inflowof the liquid, is arranged between the optical element disposed at theterminal end of the substrate alignment system 5 and a metal fixturewhich holds the optical element. Those usable for the arrangement of themask alignment system 6 include, for example, those disclosed inJapanese Patent Application Laid-open Nos. 7-176468 and 58-7823.

The liquid supply mechanism 10 includes a liquid supply unit 11 which iscapable of supplying the predetermined liquid LQ onto the substrate P inorder to form the liquid immersion area AR2 and feeding the liquid LQ,and supply nozzles 13 which are connected to the liquid supply unit 11via a supply tube 12 and which have supply ports for supplying theliquid LQ, fed from the liquid supply unit 11, onto the substrate P. Thesupply nozzles 13 are arranged closely to the surface of the substrateP.

The liquid supply unit 11 includes, for example, a tank foraccommodating the liquid LQ, and a pressurizing pump. The liquid supplyunit 11 supplies the liquid LQ onto the substrate P via the supply tube12 and the supply nozzles 13. The liquid supply operation of the liquidsupply unit 11 is controlled by the control unit CONT. The control unitCONT is capable of controlling the liquid supply amount per unit time tothe surface of the substrate P by the liquid supply unit 11. The liquidsupply unit 11 further includes a temperature-adjusting mechanism forthe liquid LQ. The liquid LQ, which has approximately the sametemperature (for example, 23° C.) as the temperature in the chamber foraccommodating the apparatus therein, is supplied onto the substrate P.It is not necessarily indispensable that the exposure apparatus EX isprovided with the tank and the pressurizing pump which are used tosupply the liquid LQ. It is also possible to utilize the equipment of afactory or the like in which the exposure apparatus EX is installed.

The liquid recovery mechanism 20 includes recovery nozzles 23 whichrecover the liquid LQ from the surface of the substrate P and which arearranged closely to the surface of the substrate P, and a liquidrecovery unit 21 which is connected to the recovery nozzles 23 via arecovery tube 22. The liquid recovery unit 21 includes, for example, avacuum system (suction unit) such as a vacuum pump, and a tank foraccommodating the recovered liquid LQ. The liquid recovery unit 21recovers the liquid LQ from the surface of the substrate P through therecovery nozzles 23 and the recovery tube 22. The liquid recoveryoperation of the liquid recovery unit 21 is controlled by the controlunit CONT. The control unit CONT is capable of controlling the liquidrecovery amount per unit time by the liquid recovery unit 21. It is notnecessarily indispensable that the exposure apparatus EX is providedwith the tank and the vacuum system for recovering the liquid LQ. It isalso possible to utilize the equipment of a factory or the like in whichthe exposure apparatus EX is installed.

FIG. 2 shows a front view illustrating those disposed in the vicinity ofthe end portion of the projection optical system PL of the exposureapparatus EX, the liquid supply mechanism 10, and the liquid recoverymechanism 20. During the scanning exposure, an image of a pattern of apart of the mask M is projected onto the projection area AR1 disposedjust under the optical element 2 disposed at the end portion of theprojection optical system PL. The mask M is moved at the velocity V inthe −X direction (or in the +X direction) with respect to the projectionoptical system PL, in synchronization with which the substrate P ismoved at the velocity β·V (β is the projection magnification) in the +Xdirection (or in the −X direction) via the XY stage 53. After thecompletion of the exposure for one shot area, the next shot area ismoved to the scanning start position in accordance with the stepping ofthe substrate P. The exposure process is successively performedthereafter for each of the shot areas in the step-and-scan manner. Thisembodiment is designed so that the liquid LQ is flowed along with themovement direction of the substrate P.

FIG. 3 shows the positional relationship among the projection area AR1of the projection optical system PL, the supply nozzles 13 (13A to 13C)for supplying the liquid LQ in the X axis direction, and the recoverynozzles 23 (23A, 23B) for recovering the liquid LQ. In FIG. 3, theprojection area AR1 of the projection optical system PL has arectangular shape which is long in the Y axis direction. The threesupply nozzles 13A to 13C are arranged on the side in the +X direction,and the two recovery nozzles 23A, 23B are arranged on the side in the −Xdirection so that the projection area AR1 is interposed thereby in the Xaxis direction. The supply nozzles 13A to 13C are connected to theliquid supply unit 11 via the supply tube 12, and the recovery nozzles23A, 23B are connected to the liquid recovery unit 21 via the recoverytube 22. Further, the supply nozzles 15A to 15C and the recovery nozzles25A, 25B are arranged in such a positional relationship that thepositions of the supply nozzles 13A to 13C and the recovery nozzles 23A,23B are rotated by substantially 180°. The supply nozzles 13A to 13C andthe recovery nozzles 25A, 25B are alternately arranged in the Y axisdirection. The supply nozzles 15A to 15C and the recovery nozzles 23A,23B are alternately arranged in the Y axis direction. The supply nozzles15A to 15C are connected to the liquid supply unit 11 via the supplytube 16. The recovery nozzles 25A, 25B are connected to the liquidrecovery unit 21 via the recovery tube 26.

When the scanning exposure is performed by moving the substrate P in thescanning direction (−X direction) indicated by the arrow Xa, the liquidLQ is supplied and recovered with the liquid supply unit 11 and theliquid recovery unit 21 by using the supply tube 12, the supply nozzles13A to 13C, the recovery tube 22, and the recovery nozzles 23A, 23B.That is, when the substrate P is moved in the −X direction, then theliquid LQ is supplied onto the substrate P from the liquid supply unit11 through the supply tube 12 and the supply nozzles 13 (13A to 13C),and the liquid LQ is recovered to the liquid recovery unit 21 throughthe recovery nozzles 23 (23A, 23B) and the recovery tube 22. The liquidLQ flows in the −X direction so that the space between the projectionoptical system PL and the substrate P is filled therewith. On the otherhand, when the scanning exposure is performed by moving the substrate Pin the scanning direction (+X direction) indicated by the arrow Xb, thenthe liquid LQ is supplied and recovered with the liquid supply unit 11and the liquid recovery unit 21 by using the supply tube 16, the supplynozzles 15A to 15C, the recovery tube 26, and the recovery nozzles 25A,25B. That is, when the substrate P is moved in the +X direction, thenthe liquid LQ is supplied from the liquid supply unit 11 onto thesubstrate P through the supply tube 16 and the supply nozzles 15 (15A to15C), and the liquid LQ is recovered to the liquid recovery unit 21through the recovery nozzles 25 (25A, 25B) and the recovery tube 26. Theliquid LQ flows in the +X direction so that the space between theprojection optical system PL and the substrate P is filled therewith. Asdescribed above, the control unit CONT makes the liquid LQ to flow inthe same direction as the movement direction of the substrate P inaccordance with the movement direction of the substrate P by using theliquid supply unit 11 and the liquid recovery unit 21. In thisarrangement, for example, the liquid LQ, which is supplied from theliquid supply unit 11 via the supply nozzles 13, flows so that theliquid LQ is attracted and introduced into the space between theprojection optical system PL and the substrate P in accordance with themovement of the substrate P in the −X direction. Therefore, even whenthe supply energy of the liquid supply unit 11 is small, the liquid LQcan be supplied to the space between the projection optical system PLand the substrate P with ease. By switching the direction, in which theliquid LQ is made to flow, depending on the scanning direction, it ispossible to fill the space between the substrate P and the projectionoptical system PL with the liquid LQ, and it is possible to obtain thehigh resolution and the wide depth of focus, even when the substrate Pis subjected to the scanning in any one of the +X direction and the −Xdirection.

FIG. 4 shows a schematic plan view illustrating the Z stage 52 of thesubstrate stage PST as viewed from an upper position. The movementmirrors 55 are arranged on the two side surfaces of the rectangular Zstage 52, the two side surfaces being perpendicular to each other. Thesubstrate P is held at a substantially central portion of the Z stage 52by the aid of the unillustrated substrate holder PSH. As describedabove, the auxiliary plate 57, which has the flat surface havingapproximately the same height as that of the surface of the substrate P,is provided around the substrate P. The plurality of shot areas S1 toS20 as the exposure objective areas are set in a matrix form on thesubstrate P. The alignment marks 1 are formed in attendance on therespective shot areas S1 to S20 respectively. The respective shot areasare depicted in FIG. 4 such that the respective shot areas are adjacentto one another. However, the respective shot areas are actuallyseparated or away from each other. The alignment marks 1 are provided onscribe lines which are separation areas thereof.

The reference member 3 is provided at one corner of the Z stage 52. Thereference member PFM to be detected by the substrate alignment system 5and the reference member MFM to be detected by the mask alignment system6 are arranged separately in a predetermined positional relationship onthe reference member 3. An optical member such as a glass plate memberis used for the base material for the reference member 3. The patterningis performed, for example, with mutually different materials (materialshaving different light reflectances) on the base material, and thus thereference marks PFM, MFM are formed. The reference marks PFM, MFM areformed so that they are free from any difference in level. The surfaceof the reference member 3 is substantially flat. Therefore, the surfaceof the reference member 3 can also serve as the reference surface forthe focus-detecting system 4.

FIG. 5 shows the reference member 3, wherein FIG. 5A shows a plan view,and FIG. 53 shows a sectional view taken along the arrow A-A shown inFIG. 5A. The reference member 3 has a base member 33 which is formed ofa glass plate member or the like, and a first material 31 and a secondmaterial 32 which are subjected to the patterning on the base member 33and which have mutually different light reflectances. In thisembodiment, the first material 31 is composed of chromium oxide (Cr₂O₃)having the low light reflectance, and the second material 32 is composedof chromium (Cr) having the light reflectance higher than that of thechromium oxide. The reference marks PFM, MFM, each of which is formed tobe cross-shaped, are formed of chromium oxide. Chromium is arranged tosurround the circumferences of the reference marks PFM, MFM. Further,chromium oxide is arranged in outer areas of the chromium. As for thematerials to be used, there is no limitation to the combination of thematerials as described above. For example, the first material may becomposed of aluminum, and the second material may be composed ofchromium. The reference marks PFM, MFM are level difference-free markswhich are formed such that the upper surfaces of the reference marksPFM, MFM are free from any difference in level.

In order to form the level difference-free mark as described above, forexample, a chromium oxide film is provided on the base member 33 bymeans of, for example, the vapor deposition, and then grooves are formedin a predetermined area of the chromium oxide film by means of, forexample, the etching process. Chromium is provided in the grooves, andthen the upper surface is subjected to the polishing process, forexample, by means of the CMP process (chemical and mechanical polishingtreatment). Accordingly, it is possible to form the leveldifference-free mark composed of chromium oxide and chromium. The leveldifference-free mark can be also formed such that grooves are formed onthe base member 33, chromium or chromium oxide is embedded in thegrooves, and then the polishing process is performed. Alternatively, thelevel difference-free mark can be also formed such that a material suchas a photosensitive material, which is denatured or altered by theoptical treatment (or the heat treatment), is coated on the base member33, and the light (or the heat) is applied to an area corresponding tothe reference mark to be formed so that the area is denatured (forexample, discolored). Further alternatively, the upper surface of thereference member 3 can be also made free from any difference in level(flat) such that a mark is formed by means of, for example, the vapordeposition of a chromium film on the base member 33, and the surfacethereof is subjected to the coating with a light-transmissive materialsuch as quartz.

At least a part of the area of the upper surface of the reference member3, which includes the reference marks PFM, MFM, is liquid-repellent(water-repellent). In this embodiment, the entire region of the uppersurface of the reference member 3 is liquid-repellent. In thisembodiment, the upper surface of the reference member 3 isliquid-repellent by performing the liquid-repelling treatment to applythe liquid repellence. The liquid-repelling treatment includes, forexample, a coating treatment using a material having the liquidrepellence. The material having the liquid repellence includes, forexample, fluorine-based compounds, silicon compounds, and syntheticresins such as acrylic resins and polyethylene. The thin film, which isadopted for the surface treatment, may be either a single layer film ora film formed of a plurality of layers.

The upper surface of the reference member 3 may be also madeliquid-repellent by using materials having liquid repellence as thefirst and second materials 31, 32 for forming the reference marks PFM,MFM. As shown in FIG. 5C, the reference member having the flat uppersurface (free from any difference in level) can be also formed byforming the reference mark with a predetermined material such aschromium on a first glass plate member 33, overlapping a second glassplate member 34 thereon, and interposing the reference mark composed ofchromium or the like between the first and second glass plate members.In this procedure, it is enough that the liquid-repelling treatment isperformed to the second glass plate member 34 to form liquid-repellantmaterial 35 on the second glass plate member 34. Therefore, it ispossible to smoothly perform the liquid-repelling treatment.

In this embodiment, the reference marks PFM, MFM are formed to becross-shaped. However, their shapes are not limited to the cross-shapedconfigurations. It is possible to use any mark shape most appropriatefor each of the detecting systems. The reference marks PFM, MFM areillustrated while being emphasized. However, each of the reference marksPFM, MFM actually has a line width of about several μm. When a system asdisclosed in Japanese Patent Application Laid-open No. 58-7823 is usedas the mask alignment system 6, a light-transmitting portion is formedas the reference member MFM for the reference member 3. Also in thiscase, it is desirable that the upper surface of the reference member 3is made to be free from any difference in level either by embedding alight-transmissive material such as quartz in the light-transmittingportion of the reference member 3 or by coating the upper surface of thereference member 3 with a light-transmissive material. As describedabove, the upper surface of the reference member 3 is used as thereference surface for the focus-detecting system 4. However, a referencesurface of the focus-detecting system 4 may be provided on the Z stage52 separately from the reference member 3. Further, the reference member3 and the auxiliary plate 57 may be provided as an integrated body.

Next, an explanation will be made with reference to a flow chart shownin FIG. 6 about an example of the procedure for exposing the substrate Pwith the pattern of the mask M by using the exposure apparatus EXdescribed above.

The substrate P is loaded on the substrate holder PSH of the Z stage 52,and the substrate holder PSH is made to hold the substrate P (see FIG.1). The measurement process is firstly performed in a state in which theliquid LQ is absent on the substrate P before supplying the liquid LQfrom the liquid supply mechanism 10. The control unit CONT moves the XYstage 53 while monitoring the output of the laser interferometer 56 sothat the optical axis AX of the projection optical system PL is advancedalong the broken line arrow C shown in FIG. 4. During the movement, thesubstrate alignment system 5 successively detects the plurality ofalignment marks 1 formed on the substrate P accompanied with the shotareas S1 to S20 not through the liquid LQ (Step SA1).

When the substrate alignment system 5 detects the alignment mark, the XYstage 53 is stopped. The position of the substrate stage PST, which isprovided when the substrate alignment system 5 detects the alignmentmark 1, is measured by the laser interferometer 56. As a result, theposition information about each of the alignment marks 1 in thecoordinate system defined by the laser interferometer 56 is measured.The detection result of the position information about the alignmentmark 1, which is detected by using the substrate alignment system 5 andthe laser interferometer 56, is outputted to the control unit CONT. TheFIA (Field Image Alignment) system is adopted for the substratealignment system 5 of this embodiment, in which the illumination lightbeam such as the white light emitted from a halogen lamp is radiatedonto the mark while allowing the substrate stage PST to stand still tophotograph the obtained image of the mark in a predetermined imagepickup field by an image pickup element, and the position of the mark ismeasured by means of the image processing.

The substrate alignment system 5 has the detection reference position inthe coordinate system defined by the laser interferometer 56. Theposition information about the alignment mark 1 is detected as adeviation with respect to the detection reference position.

In this embodiment, the position information about the shot areas S1 toS20 is determined in accordance with the so-called EGA (Enhanced GlobalAlignment) system as disclosed, for example, in Japanese PatentApplication Laid-open No. 61-44429. Therefore, the control unit CONTdesignates at least three areas (EGA shot areas) of the plurality ofshot areas S1 to S20 formed on the substrate P. The alignment marks 1accompanied with the respective shot areas are detected by using thesubstrate alignment system 5. The substrate alignment system 5 maydetect all of the alignment marks 1 on the substrate P.

The information about the surface of the substrate P is detected by thefocus-detecting system 4 not through the liquid LQ during the movementof the XY stage 53. The focus-detecting system 4 detects the deviationbetween the surface of the substrate P and the image formation plane ofthe image of the pattern formed via the projection optical system PL andthe liquid LQ. The surface information is detected by thefocus-detecting system 4 for each of all of the shot areas S1 to S20 onthe substrate P. The detection result is stored in the control unit CONTwhile corresponding to the position of the substrate P in the scanningdirection (X axis direction). The surface information may be detected bythe focus-detecting system for only a part of the shot areas.

Subsequently, the control unit CONT determines the position informationof each of the plurality of shot areas S1 to S20 on the substrate P bymeans of the calculation process (EGA process) on the basis of thedetection results of the position information of the alignment marks 1(Step SA2).

In the EGA system, the position information (coordinate position) of thealignment mark 1 accompanied with the EGA shot area designated in StepSA1 is detected by using the substrate alignment system 5, and then theerror parameter (offset, scale, rotation, degree of perpendicularity)concerning the arrangement characteristic (position information) of theshot areas S1 to S20 on the substrate P is determined by performing thestatistical calculation based on, for example, the least square methodon the basis of the detected value and the designed value. The designedcoordinate values are corrected for all of the shot areas S1 to S20 onthe substrate P on the basis of the determined value of the parameter.Accordingly, the positional relationship is determined between thedetection reference position of the substrate alignment system 5 andeach of the shot areas on the substrate P placed on the substrate stagePST. That is, the control unit CONT can know, from the output of thelaser interferometer 56, the position at which each of the shot areas onthe substrate P is located with respect to the detection referenceposition of the substrate alignment system 5.

When the detection of the alignment mark 1 of the substrate P and thedetection of the surface information of the substrate P are completed,the control unit CONT moves the XY stage 53 so that the detection areaof the substrate alignment system 5 is positioned on the referencemember 3. The substrate alignment system 5 detects the reference markPFM on the reference member 3 in the absence of any liquid to detect theposition information of the reference mark PFM in the coordinate systemdefined by the laser interferometer 56 (Step SA3).

The detection of the position information about the reference mark PFMby using the substrate alignment system 5 results in the detection ofthe positional relationship between the reference mark PFM and thedetection reference position of the substrate alignment system 5 in thecoordinate system defined by the laser interferometer 56.

After the completion of both of the detection of the positioninformation about the alignment mark 1 using the substrate alignmentsystem 5 and the detection of the position information about thereference mark PFM on the Z stage 52, the control unit CONT moves the XYstage 53 so that the reference mark MFM on the reference member 3 can bedetected by the mask alignment system 6. The mask alignment system 6observes the reference mark MFM via the projection optical system PL.Therefore, the end portion of the projection optical system PL isopposed to the reference member 3. In this situation, the control unitCONT starts the supply and the recovery of the liquid LQ by the liquidsupply mechanism 10 and the liquid recovery mechanism 20. The spacebetween the upper surface of the reference member 3 and the end surfaceof the optical element 2 disposed at the end portion of the projectionoptical system PL is filled with the liquid LQ to form the liquidimmersion area. It is desirable that the liquid immersion area AR2 isformed on only the reference member 3. However, the liquid immersionarea AR2 may be formed to range over the reference member 3 and theauxiliary plate 57. Alternatively, the liquid immersion area AR2 may beformed to range over the reference member 3, the auxiliary plate 57, andthe substrate P.

Subsequently, the control unit CONT detects the reference member MFM viathe mask M, the projection optical system PL, and the liquid LQ by themask alignment system 6 (Step SA4).

Accordingly, the information about the projection position of the imageof the pattern of the mask M on the XY plane is detected by using thereference mark MFM via the projection optical system PL and the liquidLQ. The positional relationship between the reference mark MFM and theprojection position of the image of the pattern in the coordinate systemdefined by the laser interferometer 56 is measured. The mask alignmentsystem 6 of this embodiment adopts the VRA (Visual Reticle Alignment)system in which the light beam is radiated onto the mark, and the imagedata of the mark obtained the image pickup with a CCD camera or the likeis subjected to the image processing to detect the mark position.

The control unit CONT determines a baseline amount which is the spacingdistance (positional relationship) between the detection referenceposition of the substrate alignment system 5 and the projection positionof the image of the pattern (Step SA5).

Specifically, the positional relationship (baseline amount) between thedetection reference position of the substrate alignment system 5 and theprojection position of the image of the pattern in the coordinate systemdefined by the laser interferometer 5 is determined from the positionalrelationship between the reference mark PFM and the detection referenceposition of the substrate alignment system 5 determined in Step SA3, thepositional relationship between the reference mark MFM and theprojection position of the image of the pattern determined in Step SA4,and the predetermined positional relationship between the reference markMFM (reference member 3 b) and the reference mark PFM (reference member3 a).

When the measurement process is completed as described above, thecontrol unit CONT stops the supply operation of the liquid LQ onto thereference member 3 having been performed by the liquid supply mechanism10. On the other hand, the control unit CONT continues the recoveryoperation of the liquid LQ from the surface of the reference member 3 bythe liquid recovery mechanism 20 for a predetermined period of time.After the elapse of the predetermined period of time, the control unitCONT stops the recovery operation having been performed by the liquidrecovery mechanism 20. Accordingly, the liquid LQ is recovered from thesurface of the reference member 3. It is preferable to adopt such anarrangement that the reference member 3 and the auxiliary plate 57 areprovided as an integrated body, and the reference member 3 b and thesubstrate P are continued at approximately the same height with theauxiliary plate 57 intervening therebetween. In this arrangement, theliquid immersion area of the liquid LQ can be moved from the referencemember 3 to the substrate P in a state in which the liquid LQ isretained on the image plane side of the projection optical system PLwithout stopping the liquid supply operation performed by the liquidsupply mechanism 10.

Subsequently, the control unit CONT drives the liquid supply mechanism10 and the liquid recovery mechanism 20 in a state in which theprojection optical system PL and the substrate P are opposed to eachother to start the operation for supplying the liquid onto the substrateP and the operation for recovering the liquid from the surface of thesubstrate P. Accordingly, the liquid immersion area AR2 is formedbetween the projection optical system PL and the substrate P. After theliquid immersion area AR2 is formed on the substrate P, the plurality ofshot areas on the substrate P are subjected to the liquid immersionexposure respectively by successively projecting the image of thepattern (Step SAG).

More specifically, the XY stage 53 is moved on the basis of the positioninformation about the respective shot areas with respect to thedetection reference position of the substrate alignment system 5determined in Step SA2 and the positional relationship (baseline amount)between the detection reference position of the substrate alignmentsystem 5 and the projection position of the image of the patterndetermined in Step SA5. The respective shot areas are subjected to theliquid immersion exposure process while performing the positionaladjustment between the image of the pattern and the respective shotareas S1 to S20 on the substrate P.

When the scanning exposure is performed for each of the shot areas S1 toS20 on the substrate P, the exposure process is performed by using therespective pieces of information determined during the measurementprocess as described above. That is, the respective shot areas aresuccessively exposed while effecting the positional adjustment to theprojection position of the image of the pattern on the basis of thearrangement (position information) of the shot areas determined in StepSA2. It is also allowable to use the so-called die-by-die system inwhich the alignment mark 1 in each of the shot areas on the substrate Pis successively detected by the substrate alignment system 5 to performthe overlay exposure for the shot area. However, in this case, theliquid LQ is disposed on the substrate P during the exposure for theshot area on the substrate P, while the liquid LQ is not disposed on thesubstrate P during the detection of the alignment mark 1 by thesubstrate alignment system 5, and this operation is repeatedlyperformed. Therefore, it is preferable to adopt such a procedure thatthe arrangement (position information) of the shot areas is previouslydetermined, and the substrate P is successively moved in accordance withthe determined arrangement as in this embodiment.

During the scanning exposure for each of the shot areas S1 to S20, thepositional relationship between the surface of the substrate P and theimage plane formed through the liquid LQ is adjusted without using thefocus-detecting system 4 on the basis of the surface information of thesubstrate P determined before the supply of the liquid LQ. Thepositional relationship between the image plane and the surface of thesubstrate P may be detected through the liquid LQ during the scanningexposure to perform the adjustment without determining the surfaceinformation of the substrate P before the supply of the liquid LQ.Alternatively, the both operations may be performed.

When the scanning exposure is completed for the respective shot areas S1to S20 on the substrate P, the control unit CONT stops the liquid supplyhaving been performed by the liquid supply mechanism 10. On the otherhand, the control unit CONT continues the driving of the liquid recoverymechanism 20 for a predetermined period of time after the stop of theliquid supply by the liquid supply mechanism 10. Accordingly, the liquidLQ is recovered from the surface of the substrate P. When the liquid LQis recovered from the surface of the substrate P, the liquid LQ may berecovered while relatively moving the substrate P and the recoverynozzles 23 of the liquid recovery mechanism 20 by driving the substratestage PST.

When another substrate P′ is held on the substrate stage PST to performthe exposure after the completion of the exposure of the substrate P,the shot area of the substrate P′ and the projection position of theimage of the pattern of the mask can be subjected to the positionaladjustment without detecting the position information about thereference marks PFM, MFM on the substrate stage PST. In this procedure,the another substrate P′ is held by the substrate holder PSH on the Zstage 52, and then the position information about the alignment mark 1provided in attendance on the shot area is detected by using thesubstrate alignment system 5. Accordingly, the position informationabout each of the shot areas with respect to the detection referenceposition of the substrate alignment system 5 is determined by using theEGA process in the same manner as for the substrate P previouslysubjected to the exposure. Accordingly, the projection optical system PLcan be opposed to the substrate P′, each of the shot areas on thesubstrate P′ and the image of the pattern can be subjected to thepositional adjustment, and each of the shot areas on the substrate P′can be exposed with the image of the pattern.

When the plurality of substrate P (P′) are successively exposed asdescribed above, it is unnecessary that the operation for detecting thereference mark PFM, MFM to determine the baseline amount is performedevery time when another substrate P′ is held on the Z stage 52(substrate holder PSH). The position information about the alignmentmark 1 on the substrate P′ held (loaded) on the Z stage 52 is detected,and the substrate P′ is moved on the basis of the previously determinedbaseline amount. Accordingly, the substrate P′ and the image of thepattern can be subjected to the positional adjustment efficiently andhighly accurately. It is enough that the operation for detecting thereference mark PFM, MFM to determine the baseline amount is performed atevery predetermined period of time, for example, every time when apreset number of the substrates are processed or every time when themask is exchanged.

As described above, when the reference mark PFM on the Z stage 52 isdetected by the substrate alignment system 5, the detection is performednot through the liquid LQ. Accordingly, the reference mark PFM can besatisfactorily detected without being affected, for example, by thetemperature change of the liquid LQ. It is unnecessary that thesubstrate alignment system 5 is constructed so that the substratealignment system 5 is adapted to the liquid immersion. It is possible toutilize any conventional detecting system as it is. When the referencemark MFM on the Z stage 52 is detected by using the mask alignmentsystem 6, the detection is performed via the projection optical systemPL and the liquid LQ while filling the space disposed on the image planeside of the projection optical system PL with the liquid LQ, in the samemanner as in the liquid immersion exposure. Accordingly, it is possibleto accurately detect the projection position of the image of the patternon the basis of the detection result. The baseline amount, which is thepositional relationship (distance) between the detection referenceposition of the substrate alignment system 5 and the projection positionof the image of the pattern, can be accurately determined on the basisof the respective pieces of the position information about the substratestage PST during the detection operations of the substrate alignmentsystem 5 and the mask alignment system 6. The substrate P (shot areas S1to S20) and the image of the pattern of the mask M can be accuratelysubjected to the positional adjustment on the basis of the baselineamount even when the overlay exposure is performed for the substrate P.

In this embodiment, the mark detection is performed by the maskalignment system 6 in the state in which the liquid LQ is disposed onthe reference mark MFM (reference member 3). However, the substrate P isarranged on the substrate holder PSH of the Z stage 52 during thedetection operation. Accordingly, even if the liquid LQ flows out fromthe surface of the reference member 3, it is possible to avoid theinflow of the liquid LQ into the substrate holder PSH and into thesubstrate stage PST. Even when the liquid immersion area AR2 protrudesfrom the inner edge of the auxiliary plate 57, it is possible to avoidthe inflow of the liquid LQ into the substrate holder PSH and into thesubstrate stage PST. Therefore, it is possible to avoid the occurrenceof any inconvenience including, for example, the trouble and/or theelectric leakage of the electric equipment in the substrate stage PSTand/or the rust on the respective members in the substrate stage PSTwhich would be otherwise caused by the inflowed liquid LQ.

As described above, in this embodiment, the switching is effectedbetween a wet state in which the liquid LQ is disposed on the referencemember 3 and a dry state in which the liquid LQ is not disposed on thereference member 3 when the reference marks PFM, MFM on the referencemember 3 are detected. However, as explained with reference to FIG. 5,the reference marks PFM, MFM, which are formed on the reference member3, are free from any difference in level. Therefore, for example, evenwhen the switching is effected from the dry state to the wet state, anybubble is hardly generated at the mark portion in the liquid LQ on thereference member 3. Even when the liquid LQ is recovered from thesurface of the reference member 3 in order to effect the switching fromthe wet state to the dry state, then the liquid LQ can be recoveredsatisfactorily, and no liquid LQ remains at the mark portion. Inparticular, the liquid LQ can be recovered more satisfactorily, becausethe upper surface of the reference member 3 is liquid-repellent in thisembodiment. Therefore, for example, the mask alignment system 6 canaccurately perform the detection of the reference mark MFM without beingaffected by the bubble or the like. The substrate alignment system 5 canaccurately perform the detection of the reference mark PFM without beingaffected by any remaining liquid LQ.

In this embodiment, the liquid LQ is not disposed on the referencemember 3 when the reference mark PFM is detected by the substratealignment system 5, and the liquid LQ is disposed on the referencemember 3 when the reference mark MFM is detected by the mask alignmentsystem 6. In this arrangement, the mask side reference mark MFM and thesubstrate side reference mark PFM are detected separately (notsimultaneously). However, when the reference mark PFM and the referencemark MFM are sufficiently separated from each other on the referencemember 3, and the portion of the reference mark PFM is not exposed tothe liquid LQ, then the reference mark PFM may not be the leveldifference-free mark. Further, the mask side reference mark MFM and thesubstrate side reference mark PFM may be formed on different or distinctreference members. In this case, when the mask side reference mark MFMand the substrate side reference mark PFM are not detectedsimultaneously as in this embodiment, it is unnecessary to form theliquid immersion area on the reference member on which the referencemark PFM is formed. Therefore, it is unnecessary to make the adaptationto the liquid immersion, including, for example, the arrangement inwhich the reference mark PFM is free from any difference in level.Further, it is possible to avoid the occurrence of any water mark or thelike as well.

This embodiment is constructed as follows. That is, the positioninformation is firstly determined for the plurality of shot areas S1 toS20 on the substrate P by detecting the alignment marks 1 on thesubstrate P by the substrate alignment system 5 not through the liquidLQ (Steps SA1, SA2). Subsequently, the reference mark PFM on thesubstrate stage PST is detected not through the liquid LQ (Step SA3).Subsequently, the space on the image plane side of the projectionoptical system PL is filled with the liquid LQ, and the reference markMFM is detected by the mask alignment system 6 via the projectionoptical system PL and the liquid LQ to thereby determine the projectionposition of the image of the pattern (Step SA4). The baseline amount,which is the positional relationship (distance) between the detectionreference position of the substrate alignment system 5 and theprojection position of the image of the pattern, is accuratelydetermined (Step SA5). After that, the substrate P is subjected to theliquid immersion exposure (Step SA6). That is, in this procedure, thespace on the image plane side of the projection optical system PL is notfilled with the liquid LQ in Steps SA1 to SA3 described above, and thespace on the image plane side of the projection optical system PL isfilled with the liquid LQ in Steps SA4 to SA6 described above.Accordingly, it is possible to decrease the number of switchingoperations for switching the dry state in which the space on the imageplane side of the projection optical system PL is not filled with theliquid LQ and the wet state in which the space on the image plane sideof the projection optical system PL is filled with the liquid LQ,thereby improving the throughput. For example, when the wet state isswitched to the dry state, it is necessary to perform the operation forremoving the liquid LQ remaining, for example, on the upper surface ofthe reference member 3 after the switching. However, if the number ofthe switching operations is increased, then the number of the operationsfor removing the liquid is increased as well, and the process efficiencyis lowered. However, when the number of the switching operations isreduced, it is possible to improve the throughput.

The reference mark PFM is detected by the substrate alignment system 5(Step SA3), and then the alignment marks 1 on the substrate P aredetected (Steps SA1, SA2). Subsequently, the reference mark MFM isdetected by the mask alignment system 6 via the projection opticalsystem PL and the liquid LQ (Steps SA4, SA5), and then the substrate Pis subjected to the liquid immersion exposure process (Step SA6). Alsoin this way, it is possible to decrease the number of the switchingoperations between the dry state and the wet state in the same manner asin the embodiment of the present invention. On the other hand, as in theembodiment of the present invention, the operation for detecting thereference mark PFM by the substrate alignment system 5 and the operationfor detecting the reference mark MFM by the mask alignment system 6 viathe projection optical system PL and the liquid LQ are performedcontinuously. Therefore, it is possible to avoid the inconvenience whichwould be otherwise caused such that the detection state, which isbrought about during the operation for detecting the reference mark MFMby the mask alignment system 6, is greatly varied from the detectionstate which is brought about during the operation for detecting thereference mark PFM by the substrate alignment system 5, and the baselineamount, which is the positional relationship between the detectionreference position of the substrate alignment system 5 and theprojection position of the image of the pattern, cannot be measuredaccurately. For example, there is a possibility of the occurrence of thephysical fluctuation of the positional relationship between theprojection optical system PL and the alignment system 5, the fluctuationof the optical characteristic of the alignment system 5, and thefluctuation of the environment (temperature) on the measuring opticalpath for the laser interferometer 56 to measure the position of thesubstrate stage PST, for example, due to any thermal fluctuation of theenvironment of the exposure apparatus caused, for example, by thedifference in heat generation amount between the stopped state and thedriving state of the linear motor for driving the stage. In such asituation, if the temporal interval is large between the timing of theoperation for detecting the reference mark PFM by the substratealignment system 5 and the timing of the operation for detecting thereference mark MFM by the mask alignment system 6, there is such apossibility that the inconvenience arises, in which the baseline amountcannot be measured accurately due to the thermal fluctuation. However,when the operation for detecting the reference mark PFM by the substratealignment system 5 and the operation for detecting the reference markMFM by the mask alignment system 6 are performed continuously as in theembodiment of the present invention, it is possible to avoid theinconvenience.

In the alignment sequence shown in the flow chart shown in FIG. 6, thefollowing procedure is adopted. That is, the alignment marks 1 on thesubstrate P are detected not through the liquid (Step SA1) to performthe EGA process (Step SA2), and then the reference mark PFM is detectednot through the liquid (Step SA3). After that, the detection of thereference mark MFM is executed via the projection optical system PL andthe liquid (Step SA4). However, the order of Step SA2 and Step SA3 maybe exchanged. In this case, the detection interval between the referencemark PFM and the reference mark MFM is somewhat longer than that of thesequence shown in FIG. 6. However, it is possible to perform a smallnumber of times of the operations of the liquid supply and recovery inthe same manner as in the sequence shown in FIG. 6. Therefore, thisprocedure is advantageous in view of the throughput. In the embodimentdescribed above, the reference mark PFM and the reference mark MFM areprovided separately. However, it is also allowable that one referencemark may be detected by the substrate alignment system 5 and the maskalignment system 6. Further, the detection of the reference mark PFMwithout any liquid and the detection of the reference mark MFM throughthe liquid may be executed to determine the baseline amount, and thenthe alignment marks 1 on the substrate P may be detected.

FIGS. 7 and 8 schematically show another embodiment of the presentinvention. FIG. 7 shows a state in which the projection optical systemPL is arranged over the substrate P, and FIG. 8 shows a state in whichthe projection optical system PL is arranged over the reference member3. With reference to FIGS. 7 and 8, a recess 60 is formed on the Z stage52 in order to arrange the substrate P on the substrate holder PSH, anda recess 61 is formed on the Z stage 52 in order to arrange thereference member 3. The upper surface of the substrate P arranged in therecess 60, the upper surface of the reference member 3 arranged in therecess 61, and the upper surface of the Z stage 52 are provided so thatthey are substantially flush with one another. Accordingly, even whenthe switching is effected from the state shown in FIG. 7 to the stateshown in FIG. 8 in order to detect the reference mark MFM on thereference member 3 through the liquid LQ, the substrate stage PST can bemoved in the XY directions in a state in which the liquid LQ is retainedon the image plane side of the projection optical system PL. Of course,even when the switching is effected from the state shown in FIG. 8 tothe state shown in FIG. 7, the substrate stage PST can be moved in theXY directions in a state in which the liquid LQ is retained on the imageplane side of the projection optical system PL. When the reference markMFM on the reference member 3 is detected through the liquid LQ, it isconsidered that the following situation may arise depending on the sizeof the liquid immersion area of the liquid LQ formed on the referencemember 3. That is, a part (end) of the liquid immersion area on thereference member 3 may be arranged in the recess 60 in which thesubstrate holder PSH is arranged, during the operation for detecting thereference mark MFM. However, when the substrate P is arranged in thesubstrate holder PSH of the recess 60, it is possible to avoid theinflow of the liquid LQ into the recess 60. The recess 60 can be madeflat by arranging the substrate P. It is possible to avoid anydisturbance of the liquid immersion area which would be otherwise causedby the recess (difference in level or any stepped portion). In additionto the arrangement in which the reference member 3 formed with thereference mark is embedded in the recess 61 of the Z stage 52, it isalso allowable that the reference mark is formed directly on the uppersurface of the Z stage 52 without providing the recess 61.

The embodiment described above adopts such a sequence that the alignmentmarks 1 on the substrate P are detected, and then the reference mark MFMis detected by the mask alignment system 6. Therefore, the substrate Pfor producing the device is arranged on the substrate holder PSH duringthe operation for detecting the reference mark MFM by the mask alignmentsystem 6 through the liquid LQ. However, the following possibilityarises. That is, the baseline amount may be measured singly in somecases. In other cases, a sequence may be adopted, in which the substrateP is loaded on the substrate holder PSH after the measurement of thebaseline amount. In such a situation, it is of course possible toarrange a dummy substrate DP in the substrate holder PSH. In thisarrangement, the dummy substrate DP has approximately the same shape andthe same size as those of the substrate P for producing the device. Thedummy substrate DP may be formed of the same material as that of thesubstrate P, for example, silicon. However, various types of materialscan be used for the dummy substrate DP provided that there is no elutionof pollution matters or the like brought about by the contact with theliquid LQ. In this case, the reference mark MFM is detected via theprojection optical system PL and the liquid LQ by the mask alignmentsystem 6 in a state in which the dummy substrate DP is arranged on thesubstrate holder PSH. Subsequently, the reference mark PFM is detectedwithout any liquid LQ by the substrate alignment system 5 to measure thebaseline amount. Before or after the operation of the detection by thesubstrate alignment system 5, the dummy substrate DP is unloaded fromthe substrate holder PSH, and the substrate P for producing the deviceis loaded on the substrate holder PSH. The alignment marks 1 on thesubstrate P are detected by the substrate alignment system 5, and thenthe positional adjustment is performed for the image of the pattern andthe shot areas on the substrate P on the basis of the baseline amountand the position information about the alignment marks 1 on thesubstrate P to perform the liquid immersion exposure.

FIG. 9 shows a plan view schematically illustrating an example of anexposure apparatus EX provided with a dummy substrate library 70A forstoring the dummy substrate DP. With reference to FIG. 9, the exposureapparatus EX is provided in a chamber apparatus CH. The interior of thechamber apparatus CH is maintained to be in a predetermined environment(temperature, humidity) by an air conditioning system. The substratestage PST is provided movably in a predetermined movable range in thechamber apparatus CH. A transport unit 80, which transports thesubstrate P, is connected to the exposure apparatus EX. Acoater/developer C/D, which has a function to coat the substrate P witha photosensitive material and a function to develop the substrate Phaving been subjected to the exposure process, is connected via aninterface section IF to the transport unit 80. The transport unit 80 isprovided with a first arm section 81 and a second arm section 82 forholding and transporting the substrate P. The first and second armsections 81, 82 are moved while being guided by guide sections 81A, 82Arespectively. The first and second arm sections 81, 82 and the guidesections 81A, 82A are provided in a second chamber apparatus CH2. Thesubstrate P before undergoing the exposure process, which is coated withthe photosensitive material by the coater/developer C/D, is transportedinto the chamber apparatus CH of the exposure apparatus EX by the firstarm section 81 and the second arm section 82. When the substrate Pbefore undergoing the exposure process is loaded by the second armsection 82, the substrate stage PST is moved to the substrate exchangeposition RP. The substrate stage PST, on which the substrate P has beenloaded at the substrate exchange position RP, is moved to the exposureprocess position EP disposed under the projection optical system PL. Thesubstrate stage PST, which holds the substrate P after the completion ofthe exposure process, is moved to the substrate exchange position RP.The substrate P, for which the exposure process has been completed, isunloaded by the second arm section 82 (or another arm section) at thesubstrate exchange position RP. The substrate P is transported by thefirst arm section 81 (or another arm section) via the interface sectionIF to the coater/developer C/D.

When the dummy substrate DP is arranged on the substrate holder PSH, thecontrol unit CONT takes out the dummy substrate DP from the dummysubstrate library 70A which is the waiting place for the dummy substrateDP provided in the chamber apparatus CH, by using, for example, thesecond arm section 82. The dummy substrate DP is loaded on the substrateholder PSH of the substrate stage PST at the substrate exchange positionRP. The control unit CONT detects the reference mark MFM, for example,via the projection optical system PL and the liquid LQ by the maskalignment system 6 as described above, in a state in which the dummysubstrate DP is held by the substrate holder PSH.

When the dummy substrate DP is unloaded from the substrate stage PSTafter the completion of the detection process performed through theliquid LQ as described above, the control unit CONT firstly performs theoperation for removing the liquid LQ adhering and remaining on the dummysubstrate DP, for example, by using the liquid recovery mechanism 20.The substrate stage PST, which holds the dummy substrate DP having beensubjected to the liquid-removing process, is moved by the control unitCONT to the substrate exchange position RP. The control unit CONTunloads the dummy substrate DP from the substrate stage PST by using thesecond arm section 82 (or another arm section). The dummy substrate DPis accommodated in the dummy substrate library 70A which is the waitingplace for the dummy substrate DP.

In this embodiment, the dummy substrate library 70A is provided in thechamber apparatus CH for accommodating the exposure apparatus EX.However, as indicated by the symbol 70B in FIG. 9, the dummy substratelibrary may be provided, for example, in the second chamber apparatusCH2 for accommodating the transport unit 80. Alternatively, the dummysubstrate library may be arranged in the coater/developer C/D.

It is preferable that the dummy substrate DP has the liquid repellence.In this embodiment, the dummy substrate DP is subjected to theliquid-repelling treatment to have the liquid repellence. Theliquid-repelling treatment includes, for example, a coating treatmentusing a material having the liquid repellence. The material having theliquid repellence includes, for example, fluorine-based compounds,silicon compounds, and synthetic resins such as acrylic resins andpolyethylene. The thin film, which is adopted for the surface treatment,may be either a single layer film or a film formed of a plurality oflayers.

The liquid repellence of the dummy substrate DP is deteriorated in atime-dependent manner. Accordingly, the dummy substrate DP may beexchanged depending on the deterioration of the liquid repellence.Alternatively, the dummy substrate DP may be formed of aliquid-repellent material (for example, fluorine-based material oracrylic).

FIG. 10 schematically shows another embodiment. As shown in FIG. 10, thefollowing arrangement may also be adopted. That is, a recess 60 isformed on the Z stage 52 (substrate stage PST). A substrate holder PSH,which has a shape corresponding to the recess 60, is arranged in therecess 60, and a lifting unit 63, which moves the substrate holder PSHupwardly and downwardly, is provided in the Z stage 52. As shown in FIG.10A, the lifting unit 63 moves the substrate holder PSH upwardly so thatthe upper surface of the Z stage 52 is flush with the upper surface ofthe substrate holder PSH during the operation for detecting thereference mark MFM through the liquid LQ by the mask alignment system 6.Accordingly, it is also possible to avoid the occurrence of theinconvenience which would be otherwise caused, for example, such thatthe liquid LQ of the liquid immersion area, which is formed on thereference member 3 in order to measure the reference mark MFM throughthe liquid LQ, inflows into the Z stage (substrate stage PST). As shownin FIG. 10B, the recess 60 is provided in order that the substrate P isarranged by moving the substrate holder PSH downwardly by the liftingunit 63, when the substrate P for producing the device is held by thesubstrate holder PSH in order to perform the liquid immersion exposure.When the liquid LQ is adhered to the surface of the substrate holder PSHwhen the substrate P is placed, the substrate P may be placed afterremoving or recovering the adhered liquid LQ.

In the embodiment described above, the interior of the Z stage 52 isprevented from any inflow of the liquid LQ by holding the substrate P orthe dummy substrate DP by the substrate holder PSH when the referencemark MFM on the substrate stage PST is detected via the projectionoptical system PL and the liquid LQ. However, this prevention of theinflow is not limited to the time of the detection of the reference markMFM. It is desirable that the inflow of the liquid LQ into the Z stage52 (substrate stage PST) is avoided by holding the substrate P or thedummy substrate DP on the substrate holder PSH, or by using thearrangement as shown in FIG. 10, when the liquid immersion area AR2 isformed at the circumferential portion of the upper surface of the Zstage 52 (substrate stage PST), for example, when various types ofmeasuring sensors disposed on the Z stage 52 (substrate stage PST) areused.

As described above, the operation for detecting the reference marks PFM,MFM to determine the baseline amount may be performed at everypredetermined period of time, for example, every time when a presetnumber of the substrates are processed or every time when the mask M isexchanged. In the embodiment described above, the dummy substrate DP isheld by the substrate holder PSH, for example, when the baseline amountis measured singly before the substrate P is loaded on the substrateholder PSH. Accordingly, the interior of the substrate holder PSH andthe interior of the substrate stage PST are prevented from any inflow ofthe liquid LQ. On the other hand, when the baseline amount is measured,the operation for detecting the reference marks PFM, MFM may beperformed in order to determine the baseline amount in a state in whichthe substrate P having been already subjected to the exposure process isheld on the substrate holder PSH, in place of the state in which thedummy substrate DP is held on the substrate holder PSH. Also in thisway, the interior of the substrate holder PSH and the interior of thesubstrate stage PST can be prevented from any inflow of the liquid LQ.The substrate P having been already subjected to the exposure processmay be unloaded after the completion of the measurement of the baselineamount. That is, after the completion of the exposure for the substrateP, the position information about the reference mark PFM on thesubstrate stage PST is detected by the substrate alignment system 5, andthe position information about the reference mark MFM on the substratestage PST is detected by the mask alignment system 6 in the state inwhich the substrate P having been already subjected to the exposureprocess is held by the substrate stage PST. The baseline amount isdetermined on the basis of the detection results of the positioninformation about the reference marks PFM, MFM, and then the substrate Phaving been already subjected to the exposure process is exported fromthe substrate stage PST. Accordingly, the interior of the substrateholder PSH and the interior of the substrate stage PST can be preventedfrom any inflow of the liquid LQ.

A procedure is also conceived, in which the operation for detecting thereference marks PFM, MFM is performed in order to determine the baselineamount in a state in which the substrate P before being subjected to theexposure process is held on the substrate holder PSH. However, forexample, when the reference mark MFM is detected through the liquid LQ,there is such a high possibility that the liquid LQ may adhere to thealignment mark 1 on the substrate P before being subjected to theexposure process. The substrate alignment system 5, which detects thealignment marks on the substrate P, is constructed to perform thedetection not through the liquid LQ (in the dry state). Therefore, thedetection accuracy is consequently deteriorated if the liquid LQ adheresto the alignment mark 1 when the alignment mark 1 on the substrate Pbefore being subjected to the exposure process is detected by thesubstrate alignment system 5. Therefore, it is preferable that thesubstrate P, which is to be held by the substrate holder PSH when thereference marks PFM, MFM are detected in order to determine the baselineamount, is the substrate P after being subjected to the exposureprocess.

It is desirable that the interior of the Z stage (substrate stage PST)is prevented from any inflow of the liquid LQ by holding the substrate Por the dummy substrate DP on the substrate holder PSH or by using themechanism shown in FIG. 10 when the liquid immersion area AR2 is formedon the Z stage (substrate stage PST) even when the reference member andthe measuring member such as various types of measuring sensors are notarranged on the Z stage 52 (substrate stage PST).

More specifically, it is desirable that the formation of the liquidimmersion area AR2 on the Z stage 52 (substrate stage PST) is prohibitedwhen the recess 60 of the Z stage 52 (substrate stage PST) is notcovered with the substrate P or the dummy substrate DP irrelevant to thepresence or absence of the reference member and the measuring membersuch as various types of measuring sensors on the Z stage 52 (substratestage PST).

The control unit CONT can prohibit the liquid supply by the liquidsupply mechanism 10 and restrict the movement range of the Z stage 52(substrate stage PST) in the XY plane so that the optical element 2 ofthe projection optical system PL is not opposed to the Z stage 52(substrate stage PST), for example, when the recess 60 of the Z stage 52(substrate stage PST) is not covered with the substrate P or the dummysubstrate DP.

The control unit CONT integrally controls the operation of the entireexposure apparatus EX. Therefore, the control unit CONT can judgewhether or not the recess 60 of the Z stage 52 (substrate stage PST) iscovered with, for example, the substrate P or the dummy substrate DP.However, it is also possible to use a detector for detecting whether ornot the recess 60 is covered with the substrate P or the dummy substrateDP as described later on.

It is desirable to provide the state in which the liquid LQ is notdisposed on (not adhered to) the alignment mark 1 on the substrate P asdescribed above when the alignment mark 1 on the substrate P is detectedby the substrate alignment system 5. It is feared that the liquid LQ,which remains and adheres to the supply nozzle 13, the recovery nozzle23, or the optical element 2, may be dripped or scattered onto thesubstrate P when the substrate P before being subjected to the exposureprocess, which is loaded on the substrate stage PST, passes across theposition under the supply nozzle 13, the position under the recoverynozzle 23, or the position under the optical element 2 of the projectionoptical system PL. If the dripped liquid LQ is disposed on (adhered to)the alignment mark 1 on the substrate P, then the substrate alignmentsystem 5 cannot measure the alignment mark 1, and any measurement erroris generated. Even when the measurement can be performed, then the imageof the alignment mark 1 and the waveform signal are distorted, and themeasurement is performed erroneously. As a result, any inconveniencearises, for example, such that the alignment measurement accuracy isdeteriorated.

Further, a procedure is also conceived, in which the liquid immersionarea AR2 is formed at another position on the substrate stage PST (forexample, on the auxiliary plate 57 or on the upper surface of the Zstage 52) separately from the substrate P held by the substrate stagePST, while the substrate alignment system 5 measures the alignment mark1 on the substrate P not through the liquid LQ. Furthermore, a procedureis also conceived, in which the liquid immersion area AR2 is formed(locally) on a part of the substrate P, while the alignment mark 1 isdetected, outside the liquid immersion area AR2, by the substratealignment system 5 not through the liquid LQ. Also in this case, if theliquid LQ is scattered from the liquid immersion area AR2, and/or theliquid LQ is not recovered sufficiently, then an inconvenience arisessuch that the alignment mark 1 is measured by the substrate alignmentsystem 5 in a state in which the liquid LQ is arranged on the alignmentmark 1 on the substrate P.

Accordingly, the control unit CONT determines the movement locus of thesubstrate stage PST so that the alignment mark 1 on the substrate P,which is to be arranged in the detection area for the substratealignment system 5, does not pass across the position under the supplynozzle 13, the recovery nozzle 23, or the optical element 2 of theprojection optical system PL. The control unit CONT successivelymeasures the plurality of alignment marks 1 on the substrate Prespectively by using the substrate alignment system 5 while moving thesubstrate stage PST on the basis of the determined movement locus.

FIG. 11 explains the operation for successively measuring the pluralityof alignment marks 1 on the substrate P respectively by the substratealignment system 5. With reference to FIG. 11, the supply nozzles 13 andthe recovery nozzles 23 are arranged in the vicinity of the opticalelement 2 of the projection optical system PL. The substrate alignmentsystem 5 is arranged on the +X side of the optical element 2, the supplynozzles 13, and the recovery nozzles 23. When the plurality of alignmentmarks 1 on the substrate P are successively measured respectively byusing the substrate alignment system 5 in the positional relationship asdescribed above, the control unit CONT firstly arranges the alignmentmark 1 accompanied with the shot area provided on the most −X side onthe substrate P in the detection area of the substrate alignment system5 as shown in FIG. 11A to measure the alignment mark 1 by the substratealignment system 5. For example, the control unit CONT arranges thealignment mark 1 accompanied, for example, with the shot area S10 or S11on the substrate P (see FIG. 4) in the detection area of the substratealignment system 5. In the following description, the alignment mark 1,which is firstly measured, is referred to as “first alignment mark”.

On this assumption, when the first alignment mark 1 on the substrate Pis arranged in the detection area of the substrate alignment system 5after the substrate P before being subjected to the exposure process isloaded on the substrate stage PST at the substrate exchange position RP(see FIG. 9), the control unit CONT moves the substrate stage PST sothat at least the alignment mark 1, which is the measurement objectivefor the substrate alignment system 5 and which is included in theplurality of alignment marks 1 on the substrate P, does not pass acrossthe positions under the supply nozzles 13, the recovery nozzles 23, andthe optical element 2. Accordingly, the first alignment mark 1 isarranged in the detection area of the substrate alignment system 5without passing across, for example, the positions under the supplynozzles 13. Therefore, it is possible to avoid the inconvenience whichwould be otherwise caused such that the first alignment mark 1 ismeasured by the substrate alignment system 5 in a state in which theliquid LQ dripped, for example, from the supply nozzle 13, is disposedonto the first alignment mark 1.

After the completion of the detection of the first alignment mark 1, thecontrol unit CONT moves the substrate stage PST toward the −X side sothat a second alignment mark 1 (for example, the alignment mark 1accompanied by the shot area S12 or S9), which is provided on the +Xside as compared with the first alignment mark 1, is arranged in thedetection area of the substrate alignment system 5. In this procedure,the control unit CONT determines the movement locus of the substratestage PST so that the alignment mark 1 as the measurement objective doesnot pass across the position under the supply nozzle 13 or the like toarrive at the detection area of the substrate alignment system 5.Therefore, after the substrate P is loaded on the substrate stage PST,the second alignment mark 1 does not pass across the position under thesupply nozzle 13 or the like during the period until the secondalignment mark 1 on the substrate P is arranged in the detection area ofthe substrate alignment system 5. Therefore, the inconvenience isavoided, which would be otherwise caused such that the liquid LQ drippedfrom the supply nozzle 13 or the like is arranged on the secondalignment mark 1. It is allowable that the first alignment mark 1, whichhas been already measured by the substrate alignment system 5, passesacross the position under the supply nozzle 13 or the like.

The operation is similarly performed thereafter as shown in FIG. 11B.That is, third and fourth alignment marks 1, which are provided on the+X side as compared with the second alignment mark 1, are successivelyarranged in the detection area of the substrate alignment system 5 bythe control unit CONT to perform the measurement. The operation asdescribed above is performed by the control unit CONT by controlling thesubstrate stage-driving unit PSTN on the basis of the exposure recipewhile monitoring the position of the substrate stage PST with the laserinterferometer 56.

In this procedure, the control unit CONT moves the substrate stage PSTtoward the −X side to successively arrange the alignment marks 1 in theorder from the alignment mark 1 on the −X side to the alignment mark 1on the +X side in the detection area of the substrate alignment system5. However, when the substrate alignment system 5 is provided on the −Xside of the projection optical system PL, the substrate stage PST ismoved toward the +X side. The order of the detection of the alignmentmarks 1 is not limited to the order along with the X axis direction. Asdescribed above, it is unnecessary that all of the plurality ofalignment marks 1 provided on the substrate P are detected by thesubstrate alignment system 5. Therefore, any alignment mark 1, which isnot the measurement objective for the substrate alignment system 5, ispermitted to pass across the position under the supply nozzle 13 or thelike. In principle, it is enough that the alignment mark 1, which is themeasurement objective before being arranged in the detection area of thesubstrate alignment system 5, does not pass across the position underthe supply nozzle 13 or the like.

As explained above, the movement locus of the substrate stage PST, whichis to be set in order to arrange the alignment mark 1 in the detectionarea of the substrate alignment system 5, is determined by the controlunit CONT depending on the positional relationship between the substratealignment system 5 and the supply nozzles 13 (as well as the recoverynozzles 23 and the optical element 2). Accordingly, it is possible toavoid the inconvenience of the adhesion of the liquid LQ which would beotherwise caused by the passage of the alignment mark 1 to be measuredby the substrate alignment system 5 across the position under the supplynozzle 13 or the like. Therefore, it is possible to avoid theinconvenience which would be otherwise caused such that the substratealignment system 5 measures the alignment mark 1 in the state the liquidLQ is adhered thereto. Thus, it is possible to avoid the measurementerror and the erroneous measurement. Therefore, the rate of operation ofthe exposure apparatus EX is improved, and the exposure accuracy can bemaintained in a highly sophisticated manner.

In the case of the embodiment explained with reference to FIG. 11, thealignment marks 1 may be detected by the substrate alignment system 5 ina state in which the liquid LQ is retained on the image plane side ofthe projection optical system PL. In this procedure, the liquidimmersion area AR2 is formed on the upper surface of the substrate stagePST (Z stage 52), on the portion ranging over the upper surface of thesubstrate stage PST and the surface of the substrate P, or on thesurface of the substrate P. However, as also clarified from FIG. 11, thecontrol unit CONT determines the movement locus of the substrate stagePST so that the alignment mark 1 of the substrate P is detected by thesubstrate alignment system 5 before the alignment mark 1 makes contactwith the liquid LQ in the liquid immersion area AR2 (see FIG. 1).Therefore, it is possible to avoid the inconvenience which would beotherwise caused such that the substrate alignment system 5 measures thealignment mark 1 in a state in which the liquid LQ is adhered to thealignment mark 1.

In this embodiment, the alignment mark 1 on the substrate P does notpass across the position under the supply nozzle 13 or the like beforebeing arranged in the detection area of the substrate alignment system5. However, it is also allowable that the movement locus of thesubstrate stage PST is determined so that the reference mark PFM beforebeing arranged in the detection area of the substrate alignment system 5does not pass across the position under the supply nozzle 13 or thelike. The movement locus of the substrate stage PST is determined sothat not only the alignment marks 1 and the reference mark PFM but alsoany mark (measurement objective) on the substrate stage PST to bemeasured in the dry state does not pass across the position under themember from which the liquid LQ can be dripped. Accordingly, it ispossible to improve the mark measurement accuracy not through the liquidLQ.

The embodiment described above is illustrative of the movement locusadopted when the substrate stage PST is moved from the substrateexchange position RP to the position in the vicinity of the projectionoptical system PL (exposure process position EP) and/or when theplurality of alignment marks 1 on the substrate P are measured. However,it is preferable that the movement locus of the substrate stage PST isdetermined so that the alignment mark 1 on the substrate P does not passacross the position under the supply nozzle 13 or the like as well, forexample, when the alignment mark 1 on the substrate P is measured aftermeasuring the reference marks PFM, MFM on the reference member 3. Forexample, with reference to FIG. 12, when the reference mark MFM on thereference member 3 is measured through the liquid LQ by using the maskalignment system 6, the control unit CONT measures the reference markMFM in a state in which the liquid immersion area AR2 is formed on thereference member 3. After the measurement of the reference mark MFMthrough the liquid LQ is completed, the control unit CONT recovers theliquid LQ from the surface of the reference member 3 by using, forexample, the liquid recovery mechanism 20. When the alignment mark 1 onthe substrate P is arranged in the detection area of the substratealignment system 5 thereafter, the control unit CONT moves the XY stage53 while monitoring the output of the laser interferometer 56 so thatthe supply nozzle 13 or the like is advanced along the broken line arrowK shown in FIG. 12. The control unit CONT arranges the first alignmentmark 1 (for example, the alignment mark 1 accompanied with the shot areaS10) in the detection area of the substrate alignment system 5. Also inthis case, the alignment mark 1 before being measured by the substratealignment system 5 does not pass across the position under the supplynozzle 13 or the like. Therefore, the liquid LQ, which is dripped fromthe supply nozzle 13 or the like, is not adhered thereto.

When any detection error arises due to the adhesion of the liquid to thealignment mark 1, the following operation may be performed in the samemanner as in the case in which any detection error arises due to theadhesion of any foreign matter to the alignment mark 1. That is, thedetection of the concerning alignment mark may be stopped, and anotheralignment mark disposed in the vicinity thereof may be detected in placeof the concerning alignment mark. Alternatively, the substrate P itselfmay be handled as a defective substrate.

The mark image and the signal waveform, which are obtained when thealignment mark on the substrate P is detected in the dry state by thesubstrate alignment system 5, may be previously stored. When the markimage and/or the signal waveform, which is obtained when the alignmentmark 1 is actually detected by the substrate alignment system 5, isgreatly different from the stored data, then it is judged that theliquid adheres to at least one of the alignment mark and the opticalelement disposed at the terminal end of the substrate alignment system5, and the detection error is outputted to urge the operator or the liketo wipe out the adhered liquid.

Similarly, the mark image and the signal waveform, which are obtainedwhen the reference mark PFM is measured in the dry state by thesubstrate alignment system 5, may be stored beforehand. When the markimage and/or the signal waveform, which is actually obtained for thereference mark PFM by the substrate alignment system 5, for example,upon the measurement of the baseline amount, is greatly different fromthe stored data, then it is judged that the liquid adheres to at leastone of the reference mark PFM and the optical element disposed at theterminal end of the substrate alignment system 5, and the detectionerror is outputted to urge the operator or the like to wipe out theadhered liquid.

The mark image and the signal waveform to be stored may be obtained bythe substrate alignment system 5 in the exposure apparatus EX.Alternatively, the mark image and the signal waveform to be stored maybe obtained outside the exposure apparatus EX.

An uneven illuminance sensor 400 as disclosed, for example, in JapanesePatent Application Laid-open No. 57-117238 and a spatial image-measuringsensor 500 as disclosed, for example, in Japanese Patent ApplicationLaid-open No. 2002-14005 are provided on the substrate stage PST shownin FIG. 12. It is assumed that the measurement process is performedthrough the liquid LQ in a state in which the liquid immersion area AR2is formed on each of the measuring sensors 400, 500. Also in this case,the control unit CONT performs the liquid recovery by using, forexample, the liquid recovery mechanism 20 after the completion of themeasurement process by the sensors 400, 500. When the alignment mark 1on the substrate P is arranged in the detection area of the substratealignment system 5, the control unit CONT determines the movement locusof the substrate stage PST so that the alignment mark 1 on the substrateP as the measurement objective for the substrate alignment system 5 doespass across the position under the supply nozzle 13 or the like.

FIG. 13 schematically shows another embodiment of the present invention.With reference to FIG. 13A, the exposure apparatus EX includes anattracting and holding mechanism 90 which attracts and holds thesubstrate P on the substrate holder PSH. The attracting and holdingmechanism 90 includes suction holes 91 which are provided at a pluralityof positions on the upper surface of the substrate holder PSHrespectively, and a vacuum system 93 which is connected via a flowpassage 92 to each of the plurality of suction holes 91. The controlunit CONT drives the vacuum system 93, and thus the back surface of thesubstrate P placed on the upper surface of the substrate holder PSH isheld by vacuum suction by the aid of the suction holes 91.

The information, which relates to the pressure of the vacuum system 93or the flow passage 92 of the attracting and holding mechanism 90, ismonitored by the pressure detector 94. The pressure detector 94 iscapable of detecting whether or not the substrate P (or the dummysubstrate DP) is held on the substrate holder PSH on the basis of theinformation about the detected pressure. That is, the pressure detector94 judges that the substrate P is not held on the substrate holder PSHwhen the suction operation is executed by the attracting and holdingmechanism 90 and the pressure is not lowered. The pressure detector 94judges that the substrate P is held on the substrate holder PSH when thepressure is lowered. The detection result and the judgment result of thepressure detector 94 are outputted to the control unit CONT.

A valve 14, which opens/closes the flow passage of the supply tube 12,is provided at an intermediate position of the supply tube 12 of theliquid supply mechanism 10. The operation of the valve 14 is controlledby the control unit CONT.

When the substrate P is held on the substrate holder PSH as shown inFIG. 13A, the pressure detector 94 can detect that the substrate P isheld on the substrate holder PSH on the basis of the information aboutthe pressure as described above. When the pressure detector 94 detectsthe substrate P, the control unit CONT issues the instruction to enablethe liquid supply to the liquid supply mechanism 10 on the basis of thedetection result (judgment result) of the pressure detector 94.

On the other hand, as shown in FIG. 13B, when the substrate P is notheld on the substrate holder PSH, the pressure detector 94 can detectthat the substrate P is not held on the substrate holder PSH on thebasis of the information about the pressure. When the pressure detector94 does not detect the substrate P, the control unit CONT issues theinstruction to disable the liquid supply to the liquid supply mechanism10 on the basis of the detection result (judgment result) of thepressure detector 94. The liquid supply mechanism 10, which has receivedthe instruction of the control unit CONT, closes the flow passage of thesupply tube 12, for example, by the valve 14. Accordingly, the controlunit CONT stops the liquid supply by the liquid supply mechanism 10.

When the liquid immersion area AR2 is formed and/or the liquid supply isexecuted by the liquid supply mechanism 10 in the state in which thesubstrate P or the dummy substrate DP is not held on the substrateholder PSH as described above, there is such a possibility that theliquid LQ inflows into the substrate holder PSH and into the substratestage PST. For example, if the liquid LQ inflows into the substratestage PST, then any rust appears, and any inconvenience arises in thesliding portions and the electric equipment arranged therein. Anextremely long period of time is required for the restoration. On theother hand, if the holding surface of the substrate holder PSH catchesthe liquid LQ, an inconvenience arises such that the liquid LQ flowsinto the vacuum system 93 via the suction hole 91. If the liquid LQadheres to the holding surface of the substrate holder PSH, thefollowing inconvenience occurs as well. That is, the liquid LQ functionsas a lubricating film when the substrate P is placed, and the substrateP is held in a deviated state with respect to the desired position.Accordingly, as in the embodiment of the present invention, theoperation of the liquid supply mechanism 10 is controlled depending onwhether or not the substrate P or the dummy substrate DP is held on thesubstrate holder PSH. Accordingly, it is possible to avoid the adhesionof the liquid LQ to the holding surface of the substrate holder PSH andthe inflow of the liquid into the substrate stage PST. When thesubstrate P or the dummy substrate DP is not held on the substrateholder PSH, the control unit CONT stops the liquid supply by the liquidsupply mechanism 10. Accordingly, it is possible to avoid, for example,the inflow of the liquid into the substrate stage PST.

In this embodiment, it is judged whether or not the substrate P and/orthe dummy substrate DP is held on the substrate holder PSH on the basisof the detection result of the pressure detector 94. However, forexample, a contact type sensor for detecting the presence or absence ofthe substrate may be provided for the substrate stage PST and/or thesubstrate holder PSH, and the operation of the liquid supply mechanism10 may be controlled on the basis of an obtained detection result.Alternatively, the focus-detecting system 4 as described above may beused to judge whether or not the substrate P or the dummy substrate DPis held on the substrate holder PSH, and the operation of the liquidsupply mechanism 10 may be controlled on the basis of an obtainedresult. Further, the Z stage 52 (substrate stage PST) may be prohibitedfrom the movement to the positions under the supply nozzle 13, therecovery nozzle 23, and the optical element 2 so that the liquidimmersion area AR2 is not formed on the Z stage 52 (substrate stage PST)when the substrate P (or the dummy substrate DP) is not held on thesubstrate holder PSH.

The control unit CONT may change the movable area of the substrate stagePST depending on the detection result of the pressure detector 94. Thereis such a possibility that the liquid LQ, which remains on or adheres tothe supply nozzle 13, the recovery nozzle 23, or the optical element 2of the projection optical system PL, drips to cause the inflow into thesubstrate holder PSH and/or into the substrate stage PST, even when theliquid supply by the liquid supply mechanism 10 is stopped when thesubstrate P (or the dummy substrate DP) is not held on the substrateholder PSH as in the embodiment explained with reference to FIG. 13. Thefollowing inconvenience also arises in the situation as described above.That is, for example, any electric leakage is caused in the electricequipment in the substrate stage PST, any rust appears, and the liquidLQ flows into the vacuum system 93 via the suction hole 91. Further, theliquid LQ, which has dripped onto the holding surface of the substrateholder PSH, functions as a lubricating film, and the substrate P is heldin a state of being deviated with respect to the desired position.Accordingly, the control unit CONT changes the movable area of thesubstrate stage PST depending on the detection result of the detector 94which detects whether or not the substrate P is held on the substrateholder PSH.

Specifically, when the substrate P (or the dummy substrate DP) is notheld on the substrate holder PSH, in other words, when the pressuredetector 94 does not detect the substrate P, then the control unit CONTsets that the movable area of the substrate stage PST to be the area inwhich the substrate holder PSH is not positioned under the supplynozzles 13, the recovery nozzles 23, and the optical element 2. When thesubstrate P is not held on the substrate holder PSH, the control unitCONT moves the substrate stage PST so that the substrate holder PSH doesnot pass across the position under the supply nozzle 13 or the like,while monitoring the output of the laser interferometer 56. Accordingly,even when the liquid LQ drips from the supply nozzle 13 or the like, itis possible to avoid, for example, the inflow of the liquid LQ into thesubstrate holder PSH and into the substrate stage PST.

In the embodiment described above, the supply of the liquid LQ from thesupply nozzles 13 is started when the liquid immersion area AR2 isformed on the substrate stage PST. However, the liquid immersion areaAR2 can be also formed on the substrate stage PST such that the liquid,which is retained between the projection optical system PL and anypredetermined object different from the substrate stage PST, is notrecovered, and the liquid immersion area AR2, which is formed on thepredetermined object, is moved onto the substrate stage PST.

In the embodiment described above, the reference mark PFM and thealignment marks 1 on the substrate P are detected not through theliquid, and the detection of the reference mark MFM is executed throughthe liquid. However, the invention, which relates to, for example, theprovision of the liquid repellence of the surface of the referencemember 3, the provision of the upper surface of the reference member 3free from any difference in level, and the use of the dummy substrateDP, is also applicable when any arrangement, in which the reference markPFM and the reference mark MFM can be simultaneously detected, isadopted. The invention is also applicable when the reference mark PFMand the alignment marks 1 on the substrate P are detected through theliquid. An exposure apparatus, which is constructed such that thereference mark PFM and the reference mark MFM can be simultaneouslydetected, is disclosed, for example, in Japanese Patent ApplicationLaid-open No. 4-45512 (corresponding to U.S. Pat. No. 5,138,176),contents of which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

When the liquid immersion area and the non-liquid immersion area can beformed separately on the reference member 3, it is also allowable toadopt an arrangement in which the detection of the reference mark PFMwithout the liquid and the detection of the reference mark MFM with theliquid can be performed simultaneously, as disclosed in Japanese PatentApplication Laid-open No. 4-45512. In this case, for example, Step SA3and Step SA4 can be performed simultaneously in the alignment sequenceshown in FIG. 6. Therefore, this arrangement is advantageous in view ofthe throughput. It goes without saying that an arrangement, in which thedetection of the reference mark PFM and the detection of the referencemark MFM can be performed simultaneously, may be adopted as disclosed inJapanese Patent Application Laid-open No. 4-45512, when the substratealignment system 5 is constructed such that the reference mark PFM andthe alignment marks 1 on the substrate P are detected through theliquid.

In the embodiment described above, the two reference marks, i.e., thereference mark PFM and the reference mark MFM are provided on thereference member. However, Step SA3 and Step SA4 can be also performedby using a single reference mark (reference).

As described above, pure water is used as the liquid LQ in theembodiments of the present invention. Pure water is advantageous in thatpure water is available in a large amount with ease, for example, in thesemiconductor production factory, and pure water exerts no harmfulinfluence, for example, on the optical element (lens) and thephotoresist on the substrate P. Further, pure water exerts no harmfulinfluence on the environment, and the content of impurity is extremelylow. Therefore, it is also expected to obtain the function to wash thesurface of the substrate P and the surface of the optical elementprovided at the end surface of the projection optical system PL. Whenthe purity of pure water supplied from the factory or the like is low,it is also allowable that the exposure apparatus is provided with anultra pure water-producing unit.

It is approved that the refractive index n of pure water (water) withrespect to the exposure light beam EL having a wavelength of about 193nm is approximately 1.44. When the ArF excimer laser beam (wavelength:193 nm) is used as the light source of the exposure light beam EL, thenthe wavelength is shortened on the substrate P by 1/n, i.e., to about134 nm, and a high resolution is obtained. Further, the depth of focusis magnified about n times, i.e., about 1.44 times as compared with thevalue obtained in the air. Therefore, when it is enough to secure anapproximately equivalent depth of focus as compared with the case of theuse in the air, it is possible to further increase the numericalaperture of the projection optical system PL. Also in this viewpoint,the resolution is improved.

When the liquid immersion method is used as described above, thenumerical aperture NA of the projection optical system is 0.9 to 1.3 insome cases. When the numerical aperture NA of the projection opticalsystem is large as described above, it is desirable to use the polarizedillumination, because the image formation performance is deteriorateddue to the polarization effect in some cases with the random polarizedlight which has been hitherto used as the exposure light beam. In thiscase, it is appropriate that the linear polarized illumination, which isadjusted to the longitudinal direction of the line pattern of theline-and-space pattern of the mask (reticle), is effected so that thediffracted light of the S-polarized light component (component in thepolarization direction along with the longitudinal direction of the linepattern) is dominantly allowed to outgo from the pattern of the mask(reticle). When the space between the projection optical system PL andthe resist coated on the surface of the substrate P is filled with theliquid, the diffracted light of the S-polarized light component, whichcontributes to the improvement in the contrast, has the hightransmittance on the resist surface, as compared with the case in whichthe space between the projection optical system PL and the resist coatedon the surface of the substrate P is filled with the air (gas).Therefore, it is possible to obtain the high image formation performanceeven when the numerical aperture NA of the projection optical systemexceeds 1.0. Further, it is more effective to appropriately combine, forexample, the phase shift mask and the oblique incidence illuminationmethod (especially the dipole illumination method) adjusted to thelongitudinal direction of the line pattern as disclosed in JapanesePatent Application Laid-open No. 6-188169.

Further, it is also effective to use the combination of the obliqueincidence illumination method and the polarized illumination method inwhich the linear polarization is effected in the tangential(circumferential) direction of the circle having the center of theoptical axis as disclosed in Japanese Patent Application Laid-open No.6-53120, without being limited to only the linear polarized illumination(S-polarized illumination) adjusted to the longitudinal direction of theline pattern of the mask (reticle). In particular, when the pattern ofthe mask (reticle) includes not only the line pattern extending in onepredetermined direction, but the pattern also includes the line patternsextending in a plurality of different directions in a mixed manner, thenit is possible to obtain the high image formation performance even whenthe numerical aperture NA of the projection optical system is large, byusing, in combination, the zonal illumination method and the polarizedillumination method in which the light is linearly polarized in thetangential direction of the circle having the center of the opticalaxis, as disclosed in Japanese Patent Application Laid-open No. 6-53120as well.

In the embodiments of the present invention, the optical element 2 isattached to the end portion of the projection optical system PL.Accordingly, the lens makes it possible to adjust the opticalcharacteristics of the projection optical system PL, for example, theaberration (for example, spherical aberration and comatic aberration).The optical element, which is attached to the end portion of theprojection optical system PL, may be an optical plate which is usable toadjust the optical characteristics of the projection optical system PL.Alternatively, the optical element may be a plane parallel plate orparallel flat plate through which the exposure light beam EL istransmissive. When the optical element, which makes contact with theliquid LQ, is the plane parallel plate which is cheaper than the lens,it is enough that the plane parallel plate is merely exchangedimmediately before supplying the liquid LQ even when any substance (forexample, any silicon-based organic matter), which deteriorates thetransmittance of the projection optical system PL, the illuminance ofthe exposure light beam EL on the substrate P, and the uniformity of theilluminance distribution, is adhered to the plane parallel plate, forexample, during the transport, the assembling, and/or the adjustment ofthe exposure apparatus EX. An advantage is obtained such that theexchange cost is lowered as compared with the case in which the opticalelement to make contact with the liquid LQ is the lens. That is, thesurface of the optical element to make contact with the liquid LQ isdirtied, for example, due to the adhesion of scattered particlesgenerated from the resist by being irradiated with the exposure lightbeam EL or any impurity contained in the liquid LQ. Therefore, it isnecessary to periodically exchange the optical element. However, whenthe optical element is the cheap plane parallel plate, then the cost ofthe exchange part is low as compared with the lens, and it is possibleto shorten the time required for the exchange. Thus, it is possible tosuppress the increase in the maintenance cost (running cost) and thedecrease in the throughput.

When the pressure, which is generated by the flow of the liquid LQ, islarge between the substrate P and the optical element disposed at theend portion of the projection optical system PL, it is also allowablethat the optical element is tightly fixed so that the optical element isnot moved by the pressure, instead of making the optical element to beexchangeable.

In the embodiments of the present invention, the space between theprojection optical system PL and the surface of the substrate P isfilled with the liquid LQ. However, for example, it is also allowable toadopt an arrangement in which the space is filled with the liquid LQ insuch a state that a cover glass formed of a parallel flat plate isattached to the surface of the substrate P.

The exposure apparatus, to which the liquid immersion method is appliedas described above, is constructed such that the wafer substrate P isexposed while filling the optical path space on the outgoing side of theterminal end optical element 2 of the projection optical system PL withthe liquid (pure water). However, the optical path space, which isdisposed on the incoming side of the terminal end optical element 2 ofthe projection optical system PL, may be also filled with the liquid(pure water) as disclosed in International Publication No. 2004/019128.

The liquid LQ is water in the embodiments of the present invention.However, the liquid LQ may be any liquid other than water. For example,when the light source of the exposure light beam EL is the F₂ laser, theF₂ laser beam is not transmitted through water. Therefore, liquidspreferably usable as the liquid LQ may include, for example,fluorine-based liquid such as fluorine-based oil and perfluoropolyether(PFPE) through which the F₂ laser beam is transmissive. In this case,the portion, which makes contact with the liquid LQ, is subjected to aliquid-attracting treatment by forming, for example, a thin film with asubstance having a molecular structure containing fluorine having smallpolarity. Alternatively, other than the above, it is also possible touse, as the liquid LQ, liquids (for example, cedar oil) which have thetransmittance with respect to the exposure light beam EL, which have therefractive index as high as possible, and which are stable against thephotoresist coated on the surface of the substrate P and the projectionoptical system PL. Also in this case, the surface treatment is performeddepending on the polarity of the liquid LQ to be used.

The substrate P, which is usable in the respective embodiments describedabove, is not limited to the semiconductor wafer for producing thesemiconductor device. The applicable substrates include, for example,the glass substrate for the display device, the ceramic wafer for thethin film magnetic head, and the master plate (synthetic quartz, siliconwafer) for the mask or the reticle to be used for the exposureapparatus.

As for the exposure apparatus EX, the present invention is alsoapplicable to the scanning type exposure apparatus (scanning stepper)based on the step-and-scan system for performing the scanning exposurefor the pattern of the mask M by synchronously moving the mask M and thesubstrate P as well as the projection exposure apparatus (stepper) basedon the step-and-repeat system for performing the full field exposure forthe pattern of the mask M in a state in which the mask M and thesubstrate P are allowed to stand still, while successively step-movingthe substrate P. The present invention is also applicable to theexposure apparatus based on the step-and-stitch system in which at leasttwo patterns are partially overlaid and transferred on the substrate P.

The present invention is also applicable to a twin-stage type exposureapparatus provided with two stages which are movable independently inthe XY directions while placing process objective substrates such aswafers separately thereon. The structure and the exposure operation ofthe twin-stage type exposure apparatus are disclosed, for example, inJapanese Patent Application Laid-open Nos. 10-163099 and 10-214783(corresponding to U.S. Pat. Nos. 6,341,007, 6,400,441, 6,549,269, and6,590,634), Published Japanese Translation of PCT InternationalPublication for Patent Application No. 2000-505958 (corresponding toU.S. Pat. No. 5,969,441), and U.S. Pat. No. 6,208,407, contents of whichare incorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application.

In the case of the twin stage type exposure apparatus provided with thetwo stages, the exposure station for performing the exposure for thesubstrate and the alignment station for performing the positionaladjustment for the shot area on the substrate are provided independentlyin some cases. In this arrangement, in order to improve the throughput,a substrate on the second stage is subjected to the alignment in thealignment station when the substrate on the first stage is subjected tothe exposure in the exposure station. After the substrate on the secondstage is subjected to the alignment, the second stage is moved to theexposure station, and the substrate, which has been subjected to thepositional adjustment in the alignment station, is subjected to theexposure in the exposure station. During this process, the relativeposition with respect to the reference mark provided on the substratestage as explained in the foregoing embodiment is determined for thesubstrate on the second stage in the alignment station. When the secondstage is moved to the exposure station, the image formation position isdetermined on the basis of the reference mark in the exposure station aswell. Therefore, the reference mark, which is of the type having beenexplained in the foregoing embodiment, is effectively utilized in theexposure and alignment stations of the exposure apparatus of the twinstage type.

In the embodiment described above, the exposure apparatus, in which thespace between the projection optical system PL and the substrate P islocally filled with the liquid, is adopted. However, the presentinvention is also applicable to the liquid immersion exposure apparatusin which the entire surface of the substrate as the exposure objectiveis covered with the liquid. The structure and the exposure operation ofthe liquid immersion exposure apparatus in which the entire surface ofthe substrate as the exposure objective is covered with the liquid aredescribed in detail, for example, in Japanese Patent ApplicationLaid-open Nos. 6-124873 and 10-303114 and U.S. Pat. No. 5,825,043,contents of which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

The present invention is also applicable to the exposure apparatusprovided with the exposure stage which is movable while holding theprocess objective substrate such as the wafer and the measuring stagewhich includes measuring members such as measuring sensors and varioustypes of reference members. In this case, at least parts of thereference member and the various types of measuring sensors arranged onthe substrate stage PST in the embodiment described above can bearranged on the measuring stage. The exposure apparatus provided withthe exposure stage and the measuring stage is described, for example, inJapanese Patent Application Laid-open No. 11-135400, contents of whichare incorporated herein by reference within a range of permission of thedomestic laws and ordinances of the state designated or selected in thisinternational application.

As for the type of the exposure apparatus EX, the present invention isnot limited to the exposure apparatus for the semiconductor deviceproduction for exposing the substrate P with the semiconductor devicepattern. The present invention is also widely applicable, for example,to the exposure apparatus for producing the liquid crystal displaydevice or for producing the display as well as the exposure apparatusfor producing, for example, the thin film magnetic head, the imagepickup device (CCD), the reticle, or the mask.

When the linear motor is used for the substrate stage PST and/or themask stage MST, it is allowable to use any one of those of the airfloating type based on the use of the air bearing and those of themagnetic floating type based on the use of the Lorentz's force or thereactance force. Each of the stages PST, MST may be either of the typein which the movement is effected along the guide or of the guidelesstype in which no guide is provided. An example of the use of the linearmotor for the stage is disclosed in U.S. Pat. Nos. 5,623,853 and5,528,118, contents of which are incorporated herein by referencerespectively within a range of permission of the domestic laws andordinances of the state designated or selected in this internationalapplication.

As for the driving mechanism for each of the stages PST, MST, it is alsoallowable to use a plane motor in which a magnet unit provided withtwo-dimensionally arranged magnets and an armature unit provided withtwo-dimensionally arranged coils are opposed to one another, and each ofthe stages PST, MST is driven by the electromagnetic force. In thisarrangement, any one of the magnet unit and the armature unit isconnected to the stage PST, MST, and the other of the magnet unit andthe armature unit is provided on the side of the movable surface of thestage PST, MST.

The reaction force, which is generated in accordance with the movementof the substrate stage PST, may be mechanically released to the floor(ground) by using a frame member so that the reaction force is nottransmitted to the projection optical system PL. The method for handlingthe reaction force is disclosed in detail, for example, in U.S. Pat. No.5,528,118 (Japanese Patent Application Laid-open No. 8-166475), contentsof which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

The reaction force, which is generated in accordance with the movementof the mask stage MST, may be mechanically released to the floor(ground) by using a frame member so that the reaction force is nottransmitted to the projection optical system PL. The method for handlingthe reaction force is disclosed in detail, for example, in U.S. Pat. No.5,874,820 (Japanese Patent Application Laid-open No. 8-330224), contentsof which are incorporated herein by reference within a range ofpermission of the domestic laws and ordinances of the state designatedor selected in this international application.

As described above, the exposure apparatus EX according to theembodiment of the present invention is produced by assembling thevarious subsystems including the respective constitutive elements asdefined in claims so that the predetermined mechanical accuracy, theelectric accuracy, and the optical accuracy are maintained. In order tosecure the various accuracies, those performed before and after theassembling include the adjustment for achieving the optical accuracy forthe various optical systems, the adjustment for achieving the mechanicalaccuracy for the various mechanical systems, and the adjustment forachieving the electric accuracy for the various electric systems. Thesteps of assembling the various subsystems into the exposure apparatusinclude, for example, the mechanical connection, the wiring connectionof the electric circuits, and the piping connection of the air pressurecircuits in correlation with the various subsystems. It goes withoutsaying that the steps of assembling the respective individual subsystemsare performed before performing the steps of assembling the varioussubsystems into the exposure apparatus. When the steps of assembling thevarious subsystems into the exposure apparatus are completed, theoverall adjustment is performed to secure the various accuracies as theentire exposure apparatus. It is desirable that the exposure apparatusis produced in a clean room in which, for example, the temperature andthe cleanness are managed.

As shown in FIG. 14, the microdevice such as the semiconductor device isproduced by performing, for example, a step 201 of designing thefunction and the performance of the microdevice, a step 202 ofmanufacturing a mask (reticle) based on the designing step, a step 203of producing a substrate as a base material for the device, an exposureprocess step 204 of exposing the substrate with a pattern of the mask byusing the exposure apparatus EX of the embodiment described above, astep 205 of assembling the device (including a dicing step, a bondingstep, and a packaging step), and an inspection step 206.

According to the present invention, the alignment process can beperformed accurately. Therefore, it is possible to accurately form thedesired pattern on the substrate. Further, it is possible to avoid anyinflow of the liquid, for example, into the substrate stage.

What is claimed is:
 1. A liquid immersion exposure apparatus comprising:a projection system having a last optical element, the projection systemprojecting a beam onto a substrate through an immersion liquid; amovable stage having a holder by which the substrate is held; ameasurement member provided on the movable stage, the measurement memberhaving a measurement portion covered with a light-transmissive material;a first alignment system by which an alignment mark is detected notthrough the immersion liquid; and a second alignment system which isconfigured to receive a measurement light via the measurement memberthrough the projection system and the immersion liquid between theprojection system and the light-transmissive material of the measurementmember in order to obtain first positional information of the beam to beprojected by the projection system through the immersion liquid, whereinin order to obtain the first positional information, the movable stageis moved so that the measurement member is under the projection systemand a gap between the projection system and the measurement member isfilled with the immersion liquid.
 2. The apparatus of claim 1, wherein acoating of the light-transmissive material is applied over themeasurement portion.
 3. The apparatus of claim 1, wherein a plate of thelight-transmissive material is provided over the measurement portion. 4.The apparatus of claim 3, wherein the light-transmissive plate includesa glass plate.
 5. The apparatus of claim 1, wherein thelight-transmissive material includes quartz.
 6. The apparatus of claim1, wherein the measurement member has a liquid-repellent upper surface.7. The apparatus of claim 6, wherein the liquid-repellent upper surfaceis made by a liquid-repelling treatment.
 8. The apparatus of claim 7,wherein the liquid-repelling treatment includes a coating of aliquid-repelling material.
 9. The apparatus of claim 1, wherein themeasurement portion includes a mark.
 10. The apparatus of claim 1,wherein the measurement portion includes a light-transmitting portion.11. The apparatus of claim 10, wherein the light-transmissive materialis embedded in the light-transmitting portion.
 12. The apparatus ofclaim 1, wherein the measurement portion is made by patterning amaterial having a light reflectance.
 13. The apparatus of claim 12,wherein the material includes chromium.
 14. The apparatus of claim 12,wherein the material includes chromium oxide.
 15. The apparatus of claim12, wherein second positional information of a plurality of shot areasof the substrate is detected by detecting the alignment mark by thefirst alignment system, the beam projected by the projection systemthrough the immersion liquid and the substrate are aligned on the basisof the first and second positional informations.
 16. A devicemanufacturing method comprising: exposing a substrate using the liquidimmersion exposure apparatus defined in claim 1, and processing theexposed substrate.
 17. A liquid immersion exposure apparatus comprising:a projection system having a last optical element, the projection systemprojecting a beam onto a substrate through an immersion liquid; amovable stage having a holder by which the substrate is held; and ameasurement member provided on the movable stage, the measurement memberhaving a measurement portion covered with a light-transmissive materialand the measurement member having a liquid-repellent upper surface whichis made by a coating of a liquid-repellent material over thelight-transmissive material; wherein in order to use the measurementmember, the movable stage is moved so that the measurement member isunder the projection system and a gap between the projection system andthe measurement member is filled with the immersion liquid.
 18. Theapparatus of claim 17, wherein a plate of the light-transmissivematerial is provided over the measurement portion.
 19. The apparatus ofclaim 18, wherein the light-transmissive plate includes a glass plate.20. The apparatus of claim 18, wherein the coating of theliquid-repellent material is applied on the plate.
 21. The apparatus ofclaim 17, wherein the measurement portion includes a mark.
 22. Theapparatus of claim 17, wherein the measurement portion includes alight-transmitting portion.
 23. The apparatus of claim 17, wherein themeasurement portion is made by patterning a material having a lightreflectance.
 24. The apparatus of claim 23, wherein the materialincludes chromium.
 25. The apparatus of claim 23, wherein the materialincludes chromium oxide.
 26. A liquid immersion exposure methodcomprising: holding a substrate on a holder of a movable stage on whicha measurement member is provided, the measurement member having ameasurement portion covered with a light-transmissive material;detecting an alignment mark not through immersion liquid using a firstalignment system; obtaining first positional information of a beam to beprojected by a projection system through immersion liquid using a secondalignment system which is configured to receive a measurement light viathe measurement member through the projection system and the immersionliquid between the projection system and the light-transmissive materialof the measurement member; and projecting the beam onto the substratethrough the projection system and the immersion liquid between theprojection system and the substrate, wherein in order to obtain thefirst positional information, the movable stage is moved so that themeasurement member is under the projection system and a gap between theprojection system and the measurement member is filled with theimmersion liquid.
 27. The method of claim 26, wherein a coating of thelight-transmissive material is applied over the measurement portion. 28.The method of claim 26, wherein a plate of the light-transmissivematerial is provided over the measurement portion.
 29. The method ofclaim 28, wherein the light-transmissive plate includes a glass plate.30. The method of claim 26, wherein the light-transmissive materialincludes quartz.
 31. The method of claim 26, wherein the measurementmember has a liquid-repellent upper surface.
 32. The method of claim 31,wherein the liquid-repellent upper surface is made by a liquid-repellingtreatment.
 33. The method of claim 32, wherein the liquid-repellingtreatment includes a coating of a liquid-repelling material.
 34. Themethod of claim 26, wherein the measurement portion includes a mark. 35.The method of claim 26, wherein the measurement portion includes alight-transmitting portion.
 36. The method of claim 35, wherein thelight-transmissive material is embedded in the light-transmittingportion.
 37. The method of claim 26, wherein the measurement portion ismade by patterning a material having a light reflectance.
 38. The methodof claim 37, wherein the material includes chromium.
 39. The method ofclaim 37, wherein the material includes chromium oxide.
 40. The methodof claim 37, wherein second positional information of a plurality ofshot areas of the substrate is detected by detecting the alignment markby the first alignment system, the beam projected by the projectionsystem through the immersion liquid and the substrate are aligned on thebasis of the first and second positional informations.
 41. A devicemanufacturing method comprising: exposing a substrate using the liquidimmersion exposure method defined in claim 26, and processing theexposed substrate.